Resource Center
Resource Pool
VM Instance
A VM instance is a virtual machine instance running on a host. A VM instance has its own IP address and can access public networks and run application services.
Volume
Note: Volume management mainly involves data volumes.Concepts
- Root volume: A root volume provides support for the system operations of a VM instance.
- Data volume: A data volume provides extended storage space for a VM instance.
Considerations
- A volume attached to a VM instance cannot be attached to a VM instance of another hypervisor type. For example, a KVM VM volume cannot be attached to a VMware VM instance.
- The storage space that a volume takes up is calculated based on the virtual size of the volume. When a volume is created, the virtual size of the volume is deducted. The actual storage space that the volume takes up is small upon creation while increases along with growing data writes.
- A non-shared volume can be attached to only one VM instance. A shared volume can be created on a Ceph primary storage and SharedBlock primary storage and allows simultaneous access from multiple VM instances.
- A root volume is an integral part of a VM instance. It cannot be detached from a VM instance.
- A data volume attached to a VM instance can be detached from the VM instance and then attached to another VM instance of the same hypervisor type.
- When multiple primary storage are available, you can specify a primary
storage to create a volume. If you do not specify a primary storage when you
create a volume, note that:
- For LocalStorage primary storage, the volume is created on the primary storage with the largest available space by default.
- For NFS primary storage, the volume is created on a random primary storage by default.
- For the combination of LocalStorage and NFS primary storage or the combination of LocalStorage and SharedMountPoint (SMP) primary storage, by default, the volume is created on a primary storage that does not store the root volume of the VM instance.
- You can set the QoS for a data volume to limit its disk bandwidth. Note that an excessively low QoS may greatly lower I/O performance.
Image
- A system image contains the operating system your business runs on. You can use it to create VM instances. A system image can be of the ISO or Image type.
- A volume image contains only your business data. You can use it to create volumes. A volume image can only be of the Image type.
- Image-type images can be in the raw, qcow2, or vmdk format.
- Images are stored on backup storage. When an image is used to create a VM instance or volume, the image is downloaded to a primary storage and cached there.
Instance Offering
An instance offering defines the number of vCPU cores, memory size, network bandwidth, and other configuration settings of VM instances.
Disk Offering
A disk offering defines the capacity and other configuration settings of volumes.
A disk offering can be used to create root volumes and data volumes.
GPU Specification
A GPU specification defines the frame per second (FPS), video memory, resolution, and other configuration settings of a physical or virtual GPU. GPU specifications are categorized into physical GPU specifications and virtual GPU specifications. ZStack Cloud supports GPUs installed on hosts. In ZStack Cloud, you can directly assign a single physical GPU to a VM instance, or share it among multiple VM instances running on the same host.
Auto-Scaling Group
ZStack Cloud offers auto-scaling capabilities that can automatically add or remove VM instances from an auto-scaling group (ASG) in response to load balancing of VM instances, your business load changes, and predefined scaling policies. With the auto scaling service, you can better leverage the Cloud resources, reduce the O&M costs, and ensure smooth business operations. Currently, the auto scaling service is applicable to KVM VM instances.
Scaling Mode
- Auto Scaling
- Auto scaling includes elastic scale-out and elastic scale-in. For elastic scale-out, when your businesses are growing, VM instances will be automatically added to ensure your business continuity. For elastic scale-in, if your businesses decrease, VM instances will be automatically reduced.
- The Cloud Monitoring feature allows you to trigger the auto scaling mode and specify an endpoint to receive alarms. Supported endpoints include system endpoint, email, DingTalk, HTTP application, short message service (SMS), and Microsoft Teams.
Figure 1. Auto Scaling 
- Elastic Self-Health
- In the elastic self-health mode, an auto-scaling group monitors the health status of the VM instances within the group, automatically removes the unhealthy VM instances, and adds additional VM instances. In this regard, healthy VM instances within the group will be ensured to be automatically adjusted not lower than the minimum specified number of VM instances.
- Two types of health check are provided to trigger elastic self-health, including load balancer health check and VM health check. If you configured the load balancing service for an auto-scaling group, we recommend that you select the health check mechanism native to a load balancer.
Figure 2. Elastic Self-Health 
Snapshot
A snapshot is a point-in-time capture of data status in a volume. Before you perform a business-sensitive operation, you can schedule snapshot creation at specified time points to record the state of the root volume, data volume, or memory of a VM instance. This allows rollback in case of breakdowns. If you want to backup data for a long term, you can use the Backup Service.
VM Scheduling Policy
A VM scheduling policy is a resource orchestration policy based on which VM instances are assigned hosts to achieve the high performance and high availability of businesses.
Concepts
- ZStack Cloud provides four types of scheduling
policies, and each policy can be executed based on two execution mechanisms.
You can schedule a VM instance by associating it with different scheduling
policies and execution mechanisms to meet the needs of different business
scenarios.
- Four types of VM scheduling policies: VM Exclusive from Each Other,
VM Affinitive to Each Other, VMs Exclusive from Hosts, and VMs
Affinitive to Hosts.
- VM Exclusive from Each Other: VM instances in the same VM scheduling group should not/must not run on the same host.
- VM Affinitive to Each Other: VM instances in the same VM scheduling group should/must run on the same host.
- VMs Exclusive from Hosts: Given any one of the VM instances in a VM scheduling group and any one of the hosts in a host scheduling group, the VM instance should not/must not run the host.
- VMs Affinitive to Hosts: Given any one of the VM instances in a VM scheduling group and any one of the hosts in a host scheduling group, the VM instance should/must run the host.
- A VM scheduling policy can be executed based on either of the two
execution mechanisms: Hard and Soft. Hard execution mechanism
requires VM instances to strictly comply with their associated
scheduling policies, while Soft execution mechanisms allows for some
flexibility in policy execution when the hosts do not have
sufficient resources.
- Hard: VM instances are forcibly assigned to hosts based on the associated VM scheduling policies. For example, if you associate the VM Exclusive from Each Other policy with a VM scheduling group and select the Hard mechanism for the policy, any two of the VM instances in the scheduling group are not allowed to run on the same host. If no host is available to be scheduled based on the policy for a VM instance, the VM instance will end up failure upon startup.
- Soft: VM instances are primarily assigned to hosts based on the associated VM scheduling policies. For example, if you associate the VM Exclusive from Each Other policy with a VM scheduling group and select the Soft mechanism for the policy, any two of the VM instances in the scheduling group will primarily not run on the same host. If no host is available to be scheduled based on the policy for a VM instance, the VM instance will attempt to run on a host that does not satisfy the policy.
- Four types of VM scheduling policies: VM Exclusive from Each Other,
VM Affinitive to Each Other, VMs Exclusive from Hosts, and VMs
Affinitive to Hosts.
- A VM scheduling group is the basic unit for VM instances to associate with
the VM scheduling policies.
- A VM instance can only be added to one VM scheduling group. After the addition, the VM instance will be scheduled based on the associated scheduling policies.
- A VM scheduling group can associate with one or more scheduling policies.
- A scheduling policy can associate with one VM scheduling group.
- Deleting a VM scheduling group also deletes its associated VM scheduling policies.
- Host scheduling group is the basic unit for hosts to associate with host
scheduling policies. You can use a host scheduling group when you select
VMs Affinitive to Hosts or VMs Exclusive from Hosts
policies.
- A host can only be added to one host scheduling group. After the addition, the host will be scheduled based on the associated scheduling policies.
- A host scheduling group can associate with one or more scheduling policies.
- A scheduling policy can associate with one VM scheduling group.
- Deleting a host scheduling group also deletes its associated VM scheduling policies.
Fundamentals
- If you associate a VM scheduling group with a VM Exclusive from Each Other or VM Affinitive to Each Other scheduling policy, you do not need to specify a host scheduling group, as the VM instance will be assigned to hosts based on the policy and execution mechanism.
- If you associate a VM scheduling group with a VMs Affinitive to Hosts or VMs Exclusive from Hosts scheduling policy, you need to specify the corresponding host scheduling groups and the VM instance will be assigned to hosts based on the policy and execution mechanism.
In the following section, you will learn how the four scheduling policies work through four scenario illustrations.
- Under the Hard execution mechanism, VM3 follows the policy of VM
Exclusive from Each Other:
- If Host3 has sufficient resources, VM3 can start and run normally on Host3.
- If Host3 does not have sufficient resources, then VM3 cannot start.
- Under the Soft execution mechanism, VM3 follows the policy of VM
Exclusive from Each Other and first chooses to start on Host3:
- If Host3 has sufficient resources, VM3 can start and run normally on Host3.
- If Host3 does not have sufficient resources, VM3 tries to start on other host that has available resources. In this scenario, VM3 starts and runs on Host2.

- Under the Hard execution mechanism, VM3 follows the policy of VM
Affinitive to Each Other:
- If Host1 has sufficient resources, VM3 can start and run normally on Host1.
- If Host1 does not have sufficient resources, VM3 cannot start.
- Under the Soft execution mechanism, VM3 follows the policy of VM
Affinitive to Each Other and first chooses to start on Host1:
- If Host1 has sufficient resources, VM3 can start and run normally on Host1.
- If Host3 does not have sufficient resources, VM3 tries to start on other host that has available resources. In this scenario, VM3 starts and runs on Host2.

- Under the Hard execution mechanism, VM3 and hosts in the host scheduling
group A follow the policy of VMs Exclusive from Hosts:
- If Host1 has sufficient resources, VM3 can start and run normally on Host1.
- If Host1 does not have sufficient resources, VM3 cannot start.
- Under the Soft execution mechanism, VM3 and hosts in the host scheduling
group A follow the policy of VMs Exclusive from Hosts and VM3 first
chooses to start on Host1:
- If Host1 has sufficient resources, VM3 can start and run normally on Host1.
- If Host1 does not have sufficient resources, VM3 tries to start on other host that has available resources. In this scenario, VM3 starts and runs on Host2.

- Under the Hard execution mechanism, VM6 and hosts in the host scheduling
group A follow the policy of VMs Affinitive to Hosts:
- If Host2 or Host3 have sufficient resources, VM6 can start and run normally on Host2 or Host3.
- If Host2 and Host3 do not have sufficient resources, VM6 cannot start.
- Under the Soft execution mechanism, VM6 and hosts in the host scheduling
group A follow the policy of VMs Affinitive to Hosts and VM6 first
chooses to start on Host2 or Host3:
- If Host2 or Host3 have sufficient resources, VM6 can start and run normally on Host2 or Host3.
- If both Host2 and Host3 do not have sufficient resources, VM6 tries to start on other host that has available resources. In this scenario, VM6 starts and runs on Host1.

Advantages
- Comprehensive & Flexible:
- ZStack Cloud provides four types of scheduling policies matched with two execution mechanisms to define mutual exclusion/affinity relationships between VM instances and between VM instances and hosts. Various scheduling policies can be flexibly combined to meet the needs of all mainstream business scenarios.
- ZStack Cloud supports the association of one or more scheduling policies with multiple VM instances in the VM scheduling group, as well as the removal of these policies from the VM instances in the VM scheduling group, which is simple and efficient.
- ZStack Cloud intuitively displays the VM scheduling status and provides quick conflict resolution operations to facilitate users to grasp business scheduling dynamics in real time and make timely adjustments.
- Powerful & Reliable:
- ZStack Cloud supports exclusion/affinity between the same/different businesses, achieving business isolation/efficient communication and ensuring high business performance and reliability.
- You can flexibly configure the failure domains in VM businesses through host scheduling groups. ZStack Cloud supports single host deployment, batch hosts deployment within a single cluster, and cross-cluster hosts deployment to avoid single point of failure. This ensures business stability and improves physical resource utilization.
Use Cases
In the following part, we introduce some use cases for the VM Exclusive from Each Other (Hard/Soft) and VMs Affinitive to Hosts (Hard/Soft) scheduling policies.
- VM Exclusive from Each Other (Hard):In this case, we have two VM instances that run an active-backup database. The two VM instances are required to be deployed on different hosts to ensure business high availability.
- Example: A user deploys two VMs for hosting a main and a backup MySQL database respectively, with a requirement that the two VM instances to be deployed on different hosts to minimize the risk of business downtime. Due to automatic deployment, the user does not know which hosts have available resources. At this point, the user can choose a VM Exclusive from Each Other (Hard) policy to ensure that the two VMs run on two different hosts, ensuring the business high availability.
- VM Exclusive from Each Other (Soft):In this case, we want the nodes with different roles in Hadoop to be spread across different hosts, so as to improve the overall system performance.
- Example: When deploying a Hadoop system, the user cannot predict the total number of nodes for different roles such as namenode, datanode, jobtracker, tasktracker. However, it's clear that deploying these nodes on different hosts would enhance efficiency. The VM Exclusive from Each Other (Soft) policy can help distribute the Hadoop cluster across as many different hosts as possible, thereby alleviating I/O pressure and improving the overall system performance.
- VMs Affinitive to Hosts (Hard):In this case, we want to deploy the business VM instances on hosts with a specified CPU frequency, thereby ensuring the business stability.
- Example: A user deploys four VM instances running important businesses and requires these VM intances run on the hosts that have a high CPU frequency. Given that there are limited hosts that can meet this CPU frequency requirement, the user can choose a VMs Affinitive to Hosts (Hard) policy to force these VM instances run on the specified hosts to ensure business stability.
- VMs Affinitive to Hosts (Soft):In this case, we want VM instances that run different businesses are deployed to hosts in the same rack as much as possible, so as to facilitate efficient communication between businesses.
- Example: A user deploys four VM instances that run different businesses that require frequent intercommunication. In this case, minimizing the physical distance between the VM instances can significantly reduce communication latency. At this point, the user can choose a VMs Affinitive to Hosts (Soft) policy to deploy the VM instances on the specified hosts, thereby promoting efficient business intercommunication.
Hardware
Zone
A zone is a logical group of resources such as clusters, L2 networks, and primary storage. Zone is the largest resource scope defined in the Cloud.
- In a data center, a zone corresponds to an equipment room.
- A zone defines a visible boundary. Sub-resources within the same zone are visible mutually and can form a certain relationship. However, sub-resources within different zones are invisible mutually and cannot form mutual relationships.
Cluster
A cluster is a logical group of hosts (compute nodes). In a real data center, a cluster usually maps to a rack.
- All hosts in the same cluster must be installed with the same operating system.
- All hosts in the same cluster must have the same network configuration.
- All hosts in the same cluster must be able to access the same primary storage.
- Before a cluster can provide VM services, the cluster must have a primary storage and an L2 network attached.
- The scale of a cluster, which is the maximum number of hosts that the cluster can contain, is not limited.
The relationship between a typical cluster and its associated resources is as follows:
Cluster | Zone
You can create more than one cluster in a zone, and allocate newly created hosts to different clusters as needed.
Cluster | Primary Storage and L2 Network

Note:
- Cluster | Primary Storage
- A primary storage can be attached to one or more clusters.
- A cluster can have one or more primary storage attached.The following are primary storage of the same type that a cluster can have:
- A cluster can have one or more LocalStorage primary storage attached.
- A cluster can have one or more NFS primary storage attached.
- A cluster can have one or more SharedBlock primary storage attached.
- A cluster can have one SharedMountPoint (SMP) primary storage attached.
- A cluster can have only one Ceph primary storage attached.
- A cluster can have only one AliyunNAS primary storage attached.
- A cluster can have only one AliyunEBS primary storage attached.
The following are combinations of primary storages that a cluster can have:- A cluster can have both a LocalStorage and an NFS primary storage attached.
- A cluster can have both a LocalStorage and an SMP primary storage attached.
- A cluster can have both a LocalStorage and a SharedBlock primary storage attached.
- A cluster can have both a Ceph and a maximum of three LocalStorage primary storage attached.
- A cluster can have both a Ceph and a SharedBlock primary storage attached.
- A cluster can have both a Ceph and more than one SharedBlock primary storage attached.
The following table lists the relationship between a primary storage and a cluster.Primary Storage Cluster LocalStorage A cluster can have one or more LocalStorage primary storage attached. NFS A cluster can have one or more NFS primary storage attached. SharedBlock A cluster can have one or more SharedBlock primary storage attached. SMP A cluster can have one SMP primary storage attached. Ceph A cluster can have only one Ceph primary storage attached. AliyunNAS A cluster can have only one AliyunNAS primary storage attached. AliyunEBS A cluster can have only one AliyunEBS primary storage attached. LocalStorage + NFS A cluster can have one LocalStorage and one NFS primary storage attached. LocalStorage + SMP A cluster can have one LocalStorage and one SMP primary storage attached. LocalStorage + SharedBlock A cluster can have one LocalStorage and one SharedBlock primary storage attached. Ceph + LocalStorage A cluster can have both a Ceph and a maximum of three LocalStorage primary storage attached. Ceph + SharedBlock - A cluster can have one Ceph and one SharedBlock primary storage attached.
- A cluster can have one Ceph and multiple SharedBlock primary storage attached.
- When you attach multiple LocalStorage primary storage to a cluster, partition the corresponding URLs on the hosts before you add hosts and primary storage, and make sure that each LocalStorage is deployed on an exclusive logical volume or physical disk.
- A primary storage can be accessed by all hosts in the cluster to which the primary storage belongs.
- If a primary storage cannot be accessed by hosts in the cluster due to network typology changes in the data center, you can detach the primary storage from the cluster.
- Cluster | L2 Network
- A cluster can have one or more L2 networks attached. Also, an L2 network can be attached to one or more clusters.
- A cluster can have a VXLAN pool attached. The VNIs in the VXLAN pool can be used to create different VXLAN networks.
- One NIC can be used to create only one NoVlan network.
- For VLAN networks, different VLAN IDs represent different L2 networks.
- If hosts in a cluster no longer exist in the layer 2 broadcast domain of an L2 network due to network typology changes in the data center, you can detach the L2 network from the cluster.
Cluster | Backup Storage
No direct dependency exists between a cluster and a backup storage. A backup storage can provide services for multiple clusters.
| PS/BS | ImageStore | Ceph |
| LocalStorage | ○ | × |
| NFS | ○ | × |
| SMP | ○ | × |
| Ceph | ○ | ○ |
| SharedBlock | ○ | × |
- When primary storage are LocalStorage, NFS, or SMP, the default type for backup storage is ImageStore.
- When primary storage are NFS or SMP, you can manually mount the corresponding shared directories to the local directories of the corresponding backup storage. In this regard, both primary storage and backup storage can use the network shared storage.
- When primary storage is Ceph, you can use the primary storage in the same Ceph cluster as backup storage. You can also use the ImageStore primary storage as backup storage.
- When primary storage is SharedBlock, the default type for backup storage is ImageStore.
- When primary storage is AliyunNAS, the default type for backup storage is ImageStore.
- When primary storage is AliyunEBS, the default type for backup storage is AliyunEBS.
Host
A host provides compute, network, and storage resources for VM instances. Hosts are core resources on the Cloud. VM instances are running on hosts.

Primary Storage
A primary storage is one or more servers that store volume files of VM instances. These files include root volume snapshots, data volume snapshots, image caches, root volumes, and data volumes.
- Local Storage: This type of primary storage uses the hard disks to store disk files.
- Network Shared Storage: This type of primary storage supports NFS, Shared
Mount Point (SMP), Ceph, SharedBlock, AliyunNAS, and AliyunEBS.
- NFS primary storage uses the Network File System (NFS) to store files.
- SMP primary storage supports network shared storage provided by commonly used distributed file systems, such as MooseFS, GlusterFS, OCFS2, and GFS2.
- Ceph primary storage uses distributed block storage to store files.
- SharedBlock primary storage uses shared block storage to store files.
- AliyunNAS primary storage uses distributed files to store files.
- AliyunEBS primary storage uses distributed block storage to store files.
| Primary Storage | Cluster |
|---|---|
| LocalStorage | A cluster can have one or more LocalStorage primary storage attached. |
| NFS | A cluster can have one or more NFS primary storage attached. |
| SharedBlock | A cluster can have one or more SharedBlock primary storage attached. |
| SMP | A cluster can have one SMP primary storage attached. |
| Ceph | A cluster can have only one Ceph primary storage attached. |
| AliyunNAS | A cluster can have only one AliyunNAS primary storage attached. |
| AliyunEBS | A cluster can have only one AliyunEBS primary storage attached. |
| LocalStorage + NFS | A cluster can have one LocalStorage and one NFS primary storage attached. |
| LocalStorage + SMP | A cluster can have one LocalStorage and one SMP primary storage attached. |
| LocalStorage + SharedBlock | A cluster can have one LocalStorage and one SharedBlock primary storage attached. |
| Ceph + LocalStorage | A cluster can have both a Ceph and a maximum of three LocalStorage primary storage attached. |
| Ceph + SharedBlock |
|
Backup Storage
A backup storage is a storage server that stores VM image templates, including ISO image files.
- A backup storage must be attached to a zone before the resources in the zone can
access it. Note that you can share images across multiple zones by using the backup storage.
Figure 9. Backup Storage 
- To better manage backup storage and zones, the UI specifies that one backup storage can only correspond to one zone. In the UI, when you add a backup storage, the backup storage will be attached to the current zone by default. When you delete a zone, the backup storage attached to the zone will also be deleted.
Backup Storage Type
- ImageStore
- Stores image files by means of image slices and supports incremental storage.
- Allows you to create snapshots and images when VM instances are running or stopped.
- Allows you to clone VM instances without data volumes when these VM instances are running, paused, or stopped.
- Allows you to clone VM instances with data volumes when these VM instances are running, paused, or stopped, and with storage types of LocalStorage, NFS, SharedMountPoint (SMP), Ceph, or SharedBlock.
- Supports image synchronization across ImageStore backup storage on the same management node.
- Allows you to obtain the existing image files under the URL path in the backup storage.
- Ceph
- Stores image files by means of Ceph distributed block storage.
- Allows you to create snapshots and images when VM instances are running or stopped.
- Allows you to clone VM instances without data volumes when these VM instances are running, paused, or stopped.
- Allows you to clone VM instances with data volumes when these VM instances are running, paused, or stopped, and with the storage type of Ceph.
- Allows you to export images on the UI or backup storage.
- You can export images, copy exported image URLs, and download exported images on the UI.
- You can also export images on a backup storage.
For example, assume that the image path you use is ceph://bak-t-c9923f9821bf45498fdf9cdfa1749943/61ece0adc7244b0cbd12dafbc5494f0c.
Then, run the following command on the backup storage:rbd export -p bak-t-c9923f9821bf45498fdf9cdfa1749943 --image 61ece0adc7244b0cbd12dafbc5494f0c --path /root/export-test.image # bak-t-c9923f9821bf45498fdf9cdfa1749943 is the name of the pool where the image resides. # 61ece0adc7244b0cbd12dafbc5494f0c is the name of the image. # /root/export-test.image is the name of the exported file.
- AliyunEBS
- Stores image by means of object storage.
- Allows you to create snapshots and images when VM instances are running or stopped.
- Allows you to clone VM instances without data volumes when these VM instances are running, paused, or stopped.
- Does not allow you to clone VM instances with data volumes.
- Allows you to export images on backup storage. For more information, contact the official technical support.
Backup Storage | Primary Storage
| PS/BS | ImageStore | Ceph |
| LocalStorage | ○ | × |
| NFS | ○ | × |
| SMP | ○ | × |
| Ceph | ○ | ○ |
| SharedBlock | ○ | × |
- When primary storage are LocalStorage, NFS, or SMP, the default type for backup storage is ImageStore.
- When primary storage are NFS or SMP, you can manually mount the corresponding shared directories to the local directories of the corresponding backup storage. In this regard, both primary storage and backup storage can use the network shared storage.
- When primary storage is Ceph, you can use the primary storage in the same Ceph cluster as backup storage. You can also use the ImageStore primary storage as backup storage.
- When primary storage is SharedBlock, the default type for backup storage is ImageStore.
- When primary storage is AliyunNAS, the default type for backup storage is ImageStore.
- When primary storage is AliyunEBS, the default type for backup storage is AliyunEBS.
SAN Storage
- iSCSI storage is an SAN storage that uses the iSCSI protocol for data transmission. You can add an iSCSI SAN block as a Shared Block primary storage or pass through the block to a VM instance.
- FC storage is an SAN storage that uses the FC technology for data transmission. You can add an FC SAN block as a Shared Block primary storage or pass through the block to a VM instance. ZStack Cloud supports FC for SAN storage connection with multi-path I/O.
Scenarios
- Passes through an iSCSI or FC disk to a VM instance.
- Adds an iSCSI or FC disk as a shared block and takes the shared block as a Shared Block primary storage.
Considerations
- You can add a disk that is not attached to a VM instance as a Shared Block primary storage.
- A logical unit number (LUN) that is added as a primary storage cannot be used for other purposes.
- You can attach a disk that is not added as a primary storage to a VM instance.
- You can attach a disk to multiple VM instances or attach multiple disks to one VM instance.
- If a block device is not attached to a VM instance and the cluster where the block device resides is in normal state, you can add the block device as a Shared Block primary storage.
- A logical unit number (LUN) that is added as a primary storage cannot be used for other purposes.
- You can attach a block device that is not added as a primary storage to a VM instance.
- You can attach a block device to multiple VM instances or attach multiple block devices to one VM instance.
Physical Network
Physical Network: Real networks deployed in a physical environment, which can be divided into different categories based on their application scenarios, such as management networks, storage networks, business networks, backup networks, and migration networks. You can attach tags to a NIC port on ZStack Cloud to mark which type of network it belongs to according to your physical environment planning.
Physical Network Type
- Management Network: A network used to manage physical resources on
ZStack Cloud. The management nodes communicate
with the hosts, primary storage, backup storage, VPC vRouters, and LB
instances (performance-dedicated) on the Cloud through the management
network. If you deploy a management network, it can be automatically
identified by ZStack Cloud.
- The management networks you add in comply with the management network definition here.
- The host IP addresses displayed on ZStack Cloud belong to the management network.
- The host callback IP addresses belong to the management network.
- Storage Network: A network specified for storage services. ZStack Cloud uses a storage network to get the health status of VM instances. We recommend that you deploy a dedicated storage network to avoid possible risks.
- Business Network: A network that can be added as an L2/L3 network on and attached to VM instances on ZStack Cloud. A VM instance uses a business network to provide services.
- Backup Network: A network used to back up or recover local business data in a local backup scenario. You need to deploy a backup network if you use Backup Service.
- Migration Network: A network used for VM migrations on ZStack Cloud.

Characteristics
- The Physical Network page displays physical NIC ports (bonds and non-bonds) in fact. These NIC ports realize the network connections between hosts. You manage physical networks by managing these NIC ports.
- You can attach network-type tags to NIC ports according to your physical
environment planning. Management network tags are attached to corresponding
ports automatically by the system and other tags need to be attached by
yourself.
- If you add a management network in , the NIC port of the L2 network it belongs to is attached with a management network tag.
- The NIC port of the network to which a host IP address belongs is attached with a management network tag.
- The NIC port of the network to which a host callback IP address belongs is attached with a management network tag.
- After you attach tags to corresponding NIC ports, you can view the flow monitoring of different network types, which help you master accurate network workloads more flexibly.
Network Resource
SDN Controller
- Before you can add an SDN controller to the Cloud, you need to plan management networks in advance, and complete the basic configurations of the SDN controller.
- Currently, the Cloud supports only the H3C VCFC SDN controller.
Note: If you use
VCFC to configure hardware SDN, configure the mapping between VLAN and VXLAN
on VCFC in advance.
L2 Network Resources
VXLAN Pool
- Before you can use a VXLAN network, create a VXLAN pool in advance.
- A VXLAN pool is only a collection of VXLAN networks and cannot be used to create L3 networks.
- VXLAN pool supports two types of SDN: software SDN and hardware SDN.
- Software SDN:
- The VNI range of a software-SDN VXLAN pool can be 1-16777214.
- Hosts in the cluster to which the software-SDN VXLAN pool is
attached must have an IP address as a VXLAN tunnel endpoint
(VTEP) in the specified CIDR.
- Generally, a VTEP corresponds to a NIC IP of a compute
node within a cluster. On the Cloud, you can configure a
VTEP according to its CIDR. For example,
- Assume that the NIC IP of a compute node is 10.12.0.8, the netmask is 255.0.0.0, and the gateway is 10.0.0.1. Then, the CIDR of the VTEP is 10.0.0.1/8.
- Assume that the NIC IP of the compute node is 172.20.12.13, the netmask is 255.255.0.0, and the gateway is 172.20.0.1. Then, the CIDR of the VTEP is 172.20.0.1/16.
- When a VXLAN pool is attached to a cluster, the IP address that is associated to the VTEP will be checked without checking physical L2 devices.
- Generally, a VTEP corresponds to a NIC IP of a compute
node within a cluster. On the Cloud, you can configure a
VTEP according to its CIDR. For example,
- Hardware SDN:
- Before you can create a hardware-SDN VXLAN pool, add an SDN controller to the Cloud in advance.
- The VNI range of a hardware-SDN VXLAN pool depends on the distributed vSwitch to which an SDN controller corresponds.
- The host NIC in the cluster to which the hardware-SDN VXLAN pool is attached must connect to a switch managed by the SDN controller.
- If you use VCFC to configure hardware SDN, configure the mapping between VLAN and VXLAN on VCFC in advance.
- Software SDN:
L2 Network
- VLAN, VXLAN, and SDN can be used as an L2 network.
- An L2 network is used to provide layer 2 isolation for an L3 network.
- L2NoVlanNetwork
- You must specify the NIC name of the host.
- The hosts in the cluster to which the L2 network is attached must have NICs that share the same name.
- When the data packets of VM instances flow out of the host NIC and reach the physical switch, the data packets are not flagged with VLAN tags. Note that the physical switch must be in VLAN Access mode.
- If you create an L2 network of the L2NoVlanNetwork type, a network bridge is created based on the specified host NIC.
- L2VlanNetwork
- You must specify the host NIC name and VLAN ID. ZStack Cloud allows you to create virtual NICs and virtual switches, and supports IEEE 802.1Q VLAN trunking.
- The hosts in the cluster to which the L2 network is attached must have NICs that share the same name.
- When the data packets of VM instances flow out of the host NIC and reach the physical switch, the data packets are tagged with the specified VLAN ID.
- If you create an L2 network of the L2VlanNetwork type, a VLAN device is created based on the specified VLAN ID and then a network bridge is created based on the VLAN device.
- If you attach an L2 network of the L2NoVlanNetwork type and an L2 network of the L2VlanNetwork type or attach multiple L2 networks of the L2VlanNetwork type to a cluster, the physical switch NIC must be in Trunk mode. Besides, the VLAN ID in use must be contained in the Trunk VLAN configurations.
- VxlanNetwork
- Virtual Extensible LAN (VXLAN) is an overlay technology that allows for the creation of overlaying L2 networks. This technology can support a maximum of 16 million logical networks.
- VxlanNetwork is an implementation of the software-based VXLAN technology.
- If you create an L2 network of the VxlanNetwork type, you must specify a software SDN-based VXLAN pool. The L2 network must correspond to a VNI in the pool.
- The VTEP IPs of the hosts in the cluster to which the L2 network of the VxlanNetwork type is attached must belong to the specified VXLAN pool.
- When the data packets of VM instances flow out of the host, the host encapsulates VXLAN messages to the data packets and then sends the encapsulated data to the physical switch.
- HardwareVxlanNetwork
- Virtual Extensible LAN (VXLAN) is an overlay technology that allows for the creation of overlaying L2 networks. This technology can support a maximum of 16 million logical networks.
- HardwareVxlanNetwork is a solution to the integration with third-party hardware SDN.
- If you create an L2 network of the HardwareVxlanNetwork type, you must specify a hardware SDN-based VXLAN pool. The L2 network must correspond to a VNI in the pool.
- When the data packets of VM instances flow out of the host NICs and reach the distributed virtual switches, the data packets are flagged with the specified VLAN ID. The VLAN ID is mapped with VXLAN ID based on the SDN controlled that you add to the Cloud.
Note:
- For some OS, the NIC name in the ethX format will be changed after the system reboots. In addition, the NIC sequence will also be randomly changed. We recommend that you change the NIC name of each compute node (especially for VM instances with multiple NICs) to a non-ethX format, such as em01.
L3 Network
- A network range includes an IP range (start IP and end IP), netmask, and gateway. For example, you can specify the IP range from 172.20.12.2 to 172.20.12.255, set the netmask to 255.255.0.0, and set the gateway to 172.20.0.1. In addition, you can use a CIDR to specify a network range, such as 192.168.1.0/24.
- DNS provides DNS resolution services used for configuring VM networks.
Concepts
- Public network: Generally, a public network is a logical network that is
connected to the Internet. However, in an environment that has no access to the
Internet, you can also create a public network.
- A public network can be used in the flat network environment to create VM instances.
- A public network can be used in the VPC network environment to create VM instances that work with public networks.
- Flat network: A flat network is connected to the network where the host
is located and has direct access to the Internet. VM instances in a flat network can
access public networks by using elastic IP addresses.
- A flat network supports multiple network services, including DHCP, User Data, EIP, security group, and port mirroring.
- The network services provided by a flat network use the distributed DHCP and the distributed EIP structure.
- The DHCP service provided by a flat network also includes the DNS feature.
- The network model used in the wizard is a flat network.
- The flat network architecture based on VxlanNetwork or HardwareVxlanNetwork is supported.
- VPC network: A VPC network is a private network where VM instances can
be created. A VM instance in a VPC network can access the Internet through a VPC
vRouter.
- A VPC network provides the following network services: DHCP, User Data, DNS, SNAT, route table, EIP, port forwarding, load balancing, IPsec tunnel, security group, dynamic routing, multicast routing, VPC firewall, port mirroring, and netflow.
- The DHCP service of the VPC network uses DHCP by default.
- VPC networks mainly use custom Linux VM instances as VPC vRouters to provide network services.
- Network services can act on multiple subnets of a VPC at the same time, further improving network efficiencies.
- Supports VxlanNetwork-based VPC network architecture.
- Supports distributed routing, optimizing east-west network traffic and effectively reducing network latency.
- Dedicated network:
- Management network: A management network is used to manage physical resources
in the Cloud. For example, you can create a management network to manage access to
hosts, primary storages, backup storages, and VPC vRouters.
Note: When you create a VPC vRouter, you need an IP address
that can be interconnected between the management nodes of the
VPC vRouter. With this IP address, you can deploy an agent and
obtain messages returned by the agent. - Flow network: A flow network is a dedicated network for port mirror transmission. You can use a flow network to transmit the mirrors of data packets of NIC ports to the target ports. A flow network cannot be used for other purposes, such as creating VM instances.
- Management network: A management network is used to manage physical resources
in the Cloud. For example, you can create a management network to manage access to
hosts, primary storages, backup storages, and VPC vRouters.
- Specific network scenarios:
- Storage network: A storage network is the network specified by the shared storage. You can use a storage network to check the health state of a VM instance. We recommend that you plan for an independent storage network in advance to avoid potential risks.
- VDI network: When you create a cluster, you can specify CIDR for the VDI network in the cluster. In the VDI scenario, the network traffics generated by the protocol communication between the server side and client side use the VDI network. If you do not make any configuration to the VDI network, notice that the management network will be used by default.
- Migration network: When you create a cluster, you can specify CIDR for the migration network in the cluster. The migration network is used to migrate VM instances in the Cloud. If you do not make any configuration to the migration network, notice that the management network will be used for VM migrations.
- Image synchronization network: An image synchronization network is
used to synchronize images among ImageStore backup storages in the
same management node.
- If you deployed an independent network for synchronizing images, you can specify CIDR for the image synchronization network when you add an ImageStore backup storage.
- If you do not make any configuration to the image synchronization network, notice that the management network will be used by default.
- If you set an image synchronization network for both the source ImageStore backup storage and target one, only the image synchronization network in the target ImageStore backup storage takes effect.
- Data network: A data network is the network where data can transfer
between a compute node and a backup storage.
- Using an independent data network can avoid network congestion and improve the data transfer rate.
- If you do not make any configuration to the data network, notice that the management network will be used by default.
- Backup network: If you are using the Backup Service or the
Continuous Data Protection (CDP) service, in the local backup
scenario,both the data backup and recovery are implemented by using
the backup network.
- If you deploy an independent network for local backups, you can specify CIDR for the backup network when you add a local backup server.
- Using an independent backup network can avoid network congestion and improve the data transfer rate.
- If you do not make any configuration to the backup network, notice that the management network will be used for local backup by default.
Note:
The Backup Service and the CDP Service are separately provided in a separate module. To use this feature, purchase both the Base License and the Plus License. Note that a Base License is required before you can install a Plus License.
Considerations
- When you create a VM instance, you can specify multiple L3 networks, including flat networks, VPC networks, or a combination of flat networks and VPC networks.
- The Cloud supports multi-layer networks. In addition, the L2 networks of multi-layer networks can intercommunicate. Therefore, you need to pay a special attention to avoid the conflict of IP address spaces.
- You can use an L2 network to create multiple L3 networks. However, we recommend that unless necessary you do not create multiple L3 networks from an L2 network. This may cause the DHCP services of these L3 networks unable to work as expected.
- The network services and features supported by an L3 network are related to the
network architecture model (flat network, VPC network) and the configured
network protocol version (IPv4, IPv6). If a network is configured with both IPv4
and IPv6 protocols, servers of these two protocol types are loaded at the same
time to provide corresponding services.
IPv4 IPv6 Flat network Supported network services: DHCP, User Data, EIP, security group, and port mirroring Supported network services: DHCP, DNS, EIP, and security group VPC network Supported network services: DHCP, User Data, DNS, SNAT, route table, EIP, port forwarding, load balancing, IPsec tunnel, security group, dynamic routing, multicast routing, VPC firewall, port mirroring, and Netflow Supported network services: DHCP, DNS, and security group Supported network service: VPC vRouter HA group Supported network service: VPC vRouter HA group - If you use an L2 network of the HardwareVxlanNetwork type, the L3 network created from the L2 network supports only flat network and corresponding network services.
- If you use the Smart NIC network acceleration mode for an L2 network, you can use the L2 network to create only IPv4 VPC networks and provide corresponding network services (excluding security group and port mirroring services).
- DHCP: By default, the VPC network provides distributed DHCP services by using the flat network service module.
- DNS: A VPC vRouter can act as a DNS server to provide DNS services. The DNS address in a VM instance is the IP address of the VPC vRouter. Note that the DNS address that you set is forwarded by the VPC vRouter.
- SNAT: A VPC vRouter can provide the source network address translation (SNAT) services for VM instances. Then, the VM instances can directly access the Internet by using SNAT.
- Route table: You can manage and customize routes through route tables.
- Security group: The security group service is provided by the security group network service module. You can configure and manage firewalls for VM instances by using iptables.
- Elastic IP address (EIP): You can bind an EIP to a VPC network. Then, the public network can interconnect with the private network of the VM instance.
- Port forwarding: The port forwarding service allows a public IP address to interconnect with the private IP address of a VM instance. To be more specific, you can create port forwarding rules to allow external networks to reach specific ports of your VM instances.
- Load balancing: The load balancing service distributes your inbound traffics from a public IP address to a group of backend VM instances. Then, this service automatically checks and isolates the VM instances that are unavailable.
- IPsec tunnel: The IPsec tunnel can be used to achieve interconnection between different virtual private networks (VPNs).
- Dynamic routing: The VPC vRouter supports the Open Shortest Path First (OSPF) routing protocol, which is used to distribute routing information within a single autonomous system.
- Multicast routing: The VPC vRouter forwards the multicast information sent by the multicast source to VM instances, achieving one-to-multi-point communication in the transmission side and receiving side.
- VPC firewall: The VPC firewall filters the south-north traffic on the VPC vRouter ports, effectively protecting the VPC communication security and VPC vRouter security.
- Netflow: The Netflow service monitors and analyzes the inbound and outbound traffics of the VPC vRouter NICs. Currently, the following two types of data-flow output format are supported: Netflow V5 and Netflow V9.
VPC
A Virtual Private Cloud (VPC) is a custom network environment that consists of VPC vRouters and VPC networks. With VPC, enterprise users can build a logically isolated private cloud.
VPC vRouter and VPC Network
- A VPC vRouter is a virtual router created from a vRouter offering. By default, a VPC vRouter has two types of network: public network and management network.
- A VPC network can be used as a VPC private network, and can be attached to a VPC vRouter.

VPC Network Services
- DHCP: By default, the VPC network provides distributed DHCP services by using the flat network service module.
- DNS: A VPC vRouter can act as a DNS server to provide DNS services. The DNS address in a VM instance is the IP address of the VPC vRouter. Note that the DNS address that you set is forwarded by the VPC vRouter.
- SNAT: A VPC vRouter can provide the source network address translation (SNAT) services for VM instances. Then, the VM instances can directly access the Internet by using SNAT.
- Route table: You can manage and customize routes through route tables.
- Security group: The security group service is provided by the security group network service module. You can configure and manage firewalls for VM instances by using iptables.
- Elastic IP address (EIP): You can bind an EIP to a VPC network. Then, the public network can interconnect with the private network of the VM instance.
- Port forwarding: The port forwarding service allows a public IP address to interconnect with the private IP address of a VM instance. To be more specific, you can create port forwarding rules to allow external networks to reach specific ports of your VM instances.
- Load balancing: The load balancing service distributes your inbound traffics from a public IP address to a group of backend VM instances. Then, this service automatically checks and isolates the VM instances that are unavailable.
- IPsec tunnel: The IPsec tunnel can be used to achieve interconnection between different virtual private networks (VPNs).
- Dynamic routing: The VPC vRouter supports the Open Shortest Path First (OSPF) routing protocol, which is used to distribute routing information within a single autonomous system.
- Multicast routing: The VPC vRouter forwards the multicast information sent by the multicast source to VM instances, achieving one-to-multi-point communication in the transmission side and receiving side.
- VPC firewall: The VPC firewall filters the south-north traffic on the VPC vRouter ports, effectively protecting the VPC communication security and VPC vRouter security.
- Netflow: The Netflow service monitors and analyzes the inbound and outbound traffics of the VPC vRouter NICs. Currently, the following two types of data-flow output format are supported: Netflow V5 and Netflow V9.
Characteristics
- Flexible network configuration: Different VPC networks can be flexibly attached to the VPC vRouters. You can customize an independent IP range and an independent gateway for each VPC network. VPC vRouters allow you to attach or detach gateways, and also to dynamically configure your route tables and route entries.
- Secure and reliable isolation: Different VPC networks in different VPCs are logically isolated. That is, the VPC networks support VLAN and VXLAN for logical layer 2 isolation, and different VPCs of different accounts will not affect each other.
- Multi-subnet interconnection: Multiple VPC networks under the same VPC can communicate privately and securely with one another.
- Network traffic optimization: VPC supports distributed route features, which can optimize the east-west network traffic and reduce the network latency effectively.
- VPC vRouter HA: In a VPC vRouter HA group, you can deploy two VPC vRouters according to the active-standby policy. When the active VPC vRouter is abnormal, the standby VPC vRouter will automatically take over to work properly, thus ensuring your business continuity.
Routing Protocol Resource
Compared to static routing, dynamic routing, which can be applied to a large-scale network environment, supports automatic topology change, route recalculation, and unattended interference. A VPC vRouter supports the OSPF dynamic routing protocol.
Open Shortest Path First (OSPF): An OSPF is an interior gateway protocol of link states and is used to distribute routing information within a single autonomous system (AS). An OSPF is widely used in a data center network and a campus network.
Network Service
The Cloud provides VM instances with multiple network services, including VPC firewall, security group, virtual IP address (VIP), elastic IP address (EIP), port forwarding, IPsec tunnel, load balancing, and flow monitoring.
- Flat network
- VPC network
Network Service Module
The Network Service Module provides a group of network services. Note that this module has been hidden on the UI.
- Virtual Router Network Service Module (Not recommended)
Provides various network services: DNS, SNAT, load balancing, port forwarding, EIP, and DHCP.
- Flat Network Service Module (Flat Network Service Provider)Provides the following network services:
- User Data: Customizes some parameters, such as
ssh-keyinjection. By runningcloud-init, these parameters will be loaded and injected into your VM instance when the VM instance is started. - EIP: Allows you to access private networks through public networks.
- DHCP: Dynamically obtains an IP address.
Note: The DHCP service
includes the DNS feature. - VIP QoS: Limits the upstream and downstream bandwidth. This applies only to EIPs.
- User Data: Customizes some parameters, such as
- VPC vRouter Network Service ModuleProvides the following network services:
- IPsec: Achieves VPN connections.
- vRouter route table: Manages custom routes.
- Centralized DNS: Provides the DNS service when the distributed DHCP service is enabled.
- VIP QoS: Limits the upstream and downstream bandwidth of a virtual IP address.
- DNS: Uses VPC vRouters to provide the DNS service.
- SNAT: Enables VM instances to access the Internet directly.
- Load balancing: Distributes inbound traffics from a VIP to a group of backend VM instances. Then, unavailable VM instances will be detected and isolated automatically.
- Port forwarding: Forwards port traffics of specified public IP addresses to the ports of corresponding VM instances according to specified protocols.
- EIP: Uses VPC vRouters to access private networks of VM instances through public networks.
- DHCP: Provides the centralized DHCP service.
- Security Group Network Service ModuleProvides the following network service:
- Security group: Manipulates securities of VM instance firewalls by using iptables.
Flat Network Practice
- Flat Network Service Module
- User Data: Customizes some parameters, such as
ssh-keyinjection. By runningcloud-init, these parameters will be loaded and injected into your VM instance when the VM instance is started. - EIP: Allows you to access private networks through public networks.
- DHCP: Dynamically obtains an IP address.
Note: The DHCP service
includes the DNS feature.
- User Data: Customizes some parameters, such as
- Security Group Network Service Module
- Security group: Manipulates securities of VM instance firewalls by using iptables.
VPC Network Practice
- Flat Network Service Module
- User Data: Customizes some parameters, such as
ssh-keyinjection. By runningcloud-init, these parameters will be loaded and injected into your VM instance when the VM instance is started. - DHCP: Dynamically obtains an IP address.
- User Data: Customizes some parameters, such as
- vRouter Network Service Module
- DNS: Uses vRouters to provide the DNS service.
- SNAT: Allows VM instances to access directly the Internet.
- vRouter route table: Manages custom routes.
- EIP: Uses vRouters to access private networks of VM instances through public networks.
- Port forwarding: Forwards port traffics of specified public IP addresses to the ports of corresponding VM instances according to specified protocols.
- Load balancing: Distributes inbound traffics from a VIP to a set of backend VM instances. Then, unavailable VM instances will be detected and isolated automatically.
- IPsec: Achieves VPN connections.
- Security Group Network Service Module
- Security group: Manipulates securities of VM instance firewalls by using iptables.
Advanced Network Services
- Dynamic routing: Uses the Open Shortest Path First (OSPF) routing protocol to distribute routing information within a single autonomous system. This service applies to VPC network scenarios.
- Multicast routing: Forwards the multicast information sent by the multicast source to VM instances, achieving one-to-multi-point communication in the transmission side and receiving side. This service applies to VPC network scenarios.
- VPC firewall: Filters the south-north traffic on the VPC vRouter ports, effectively protecting the VPC communication security and VPC vRouter security. This service applies to VPC network scenarios.
- Port mirroring: Copies and sends network traffics of VM NICs from a port to another port, and analyzes the business packets on the ports, better monitoring and managing the network data. This service applies to flat network, vRouter network, and VPC network scenarios.
- Netflow: Monitors and analyzes the inbound and outbound traffics of the VPC vRouter NICs. Currently, the following two types of data-flow output formats are supported: Netflow V5 and Netflow V9. This service applies to VPC network scenarios.
Security Group
A security group provides security control services for VM NICs. It filters the ingress or egress TCP, UDP, and ICMP packets of VM NICs based on the specified security rules.
Characteristics
Security Group and Security Rule
- Security rules filter flows based on the flow source or flow destination.
They can be categorized into the following two types based on the direction
of flows they control:
- Ingress Rule: Ingress rules take effect on flows accessing VM NICs. They are responsible for filtering ingress flow sources.
- Egress Rule: Egress rules take effect on flows out of VM NICs. They are responsible for filtering egress flow destinations.
- You can set IP addresses or other security group as flow
sources/destinations of security rules.
- IP address as source: A source IP is filtered by ingress rules. The rules may allow or reject the flows from this IP address to access VM NICs.
- Security group as source: A source security group is filtered by ingress rules. The rules may allow or reject the flows from this security group to access VM NICs.
- IP address as destination: A destination IP is filtered by egress rules. The rules may allow or reject VM NICs to access this IP address.
- Security group as destination:A destination security group is filtered by egress rules. The rules may allow or reject VM NICs to access this security group.
- You can set priorities for rules on the same direction. The highest rule take effect when a conflict occurs in such a scenario as you set more than one rule, especially an allow rule and a reject rule, on the same source or destination.
- By default, mutual communications among NICs in the same security group are allowed and the system automatically add corresponding ingress/egress rules to the security group to ensure these mutual communication. These default rules cannot be modified or deleted. If you want to cancel the mutual communications, just disable these rules.
Security Group and VM NIC
- If you attach more than one security groups to a VM NIC, you can set
priorities for these groups. The NIC matches the rules of the group with the
highest priority first, and then the group of lower priorities.
Note: By
default, all admin security group have higher priority than user
security groups. - After attached to security groups, you need to set a default flow policy to process the flows that are not stipulated by security group rules. By default, all ingress rules that are not stipulated are rejected and all egress rules that are not stipulated are allowed.
Security Group and Permission
- A tenant/sub-account can view and manage security groups owned by itself.
- The administrator can view and manage all security group. When attach security groups to NICs, note that an admin security group can be attached to any NIC, while To a tenant/sub-account security group can be attached to only NICs owned by the same tenant/sub-account.
Considerations
- If you use a security group along with other network services, such as load balancing and route table, make sure that the security group rules required by these network services are added to the security group.
- Public networks, flat networks, and VPC networks support the security group service. It is provided by the security group network service module, which uses iptables to implement security control.
- A security group is a distributed firewall. Each security rule change, NIC association or disassociation will cause the security group rule to be updated on all associated VM instances.
Virtual IP
- VIPs created from a public network can provide network services such as EIP and load balancing for flat networks.
- VIPs created from a public network can provide network services, such as EIP, port forwarding, load balancing, and IPsec tunnel, for VPC networks.
- VIPs created from a VPC network can provide load balancing services for VPC networks.
- VIPs created from a flat network can provide network services, such as EIP and load balancing, for flat networks.
You can use a VIP to provide performance-shared load balancing services. A performance-shared load balancer uses a VPC vRouter to provide load balancing services. Traffic is distributed to backend servers by the VPC vRouter. If the VPC vRouter is providing multiple services, the load balancing service shares the performance of the VPC vRouter along with other services.

Concepts
- Public VIP: VIPs created from a public network. You can manually create a
public VIP or use a public VIP automatically created after a VPC vRouter
creation.
- A public VIP can provide network services, such as EIP and load balancing, for flat networks. A public VIP can also provide network services, such as EIP, port forwarding, load balancing, and IPsec tunnel, for VPC networks.
- You can use a public VIP to simultaneously provide port forwarding, load balancing, and IPsec tunnel services. You can also use a public VIP to provide one service for multiple VM instances. However, you cannot specify the same port number for different services.
- A public VIP supports QoS, monitoring data, performance TOP 5, performance analysis, alarm, and other features.
- VPC VIP: VIPs created from a VPC network. A VPC VIP can only be manually
created.
- A VPC VIP can provide load balancing services for VPC networks.
- VPC VIPs do not support QoS, monitoring data, performance TOP 5, performance analysis, and alarm features.
- Flat network VIP: VIPs created from a flat network. You can manually create
a flat network VIP or use a flat network VIP automatically created after a
VPC vRouter creation.
- A flat network VIP provides network services, such as EIP and load balancing, for flat networks.
- A flat network VIP supports QoS, monitoring data, performance TOP 5, performance analysis, alarm, and other features.
- Custom VIP: manually created VIPs. You can customize a public VIP, VPC VIP,
and flat network VIP based on your needs.
- One custom public VIP can only be applied to one EIP instance.
- Custom VIPs cannot be used across VPC vRouters.
- When you use the EIP, port forwarding, load balancing, or IPsec tunnel services, you can select Create VIP to create a new VIP, or you can select Use Existing VIP to provide the services.
- System VIP: VIPs automatically created by using the L3 network attached to
VPC vRouters after the VPC vRouter creation. System VIPS can be categorized
into public VIPs and flat network VIPs.
- A system VIP belongs to only one VPC vRouter. When you attach a public network to a VPC vRouter, the Cloud will automatically create a system VIP. This VIP is the default IP address of the vRouter in the network.
- By default, the system VIPs created from public networks are used to provide the source network address translation (SNAT) service.
- When you use the EIP, port forwarding, load balancing, or IPsec tunnel service, you can select Use Existing VIP to provide the services.
Elastic IP
An elastic IP address (EIP) functions based on the NAT technology. IP addresses in a private network are translated into an EIP that is in another network. This way, private networks can be accessed from other networks by using EIPs.
Concepts
- Public EIP: The EIP service provided by a virtual IP address (VIP) created
from a public network.
- The private network is an isolated network that cannot be directly accessed from other networks or the Internet. A public EIP can directly associate the access to a public network with the VM IP of the private network.
- A public EIP can be associated with or disassociated from a VM instance dynamically.
- A public EIP can be associated with VM instances created from
private networks, such as flat networks and VPC networks.
- The public EIP realized by a distributed EIP can access flat networks through public networks.
- A VPC vRouter can be used to access VPC networks through public networks.
- Flat EIP: The EIP service provided by a VIP created from a flat network.
- L3 isolations exist between flat networks of different network ranges. Therefore, these flat networks cannot be accessed directly. A flat EIP can be used to associate the access to one flat network with the VM IP created from another flat network.
- A flat EIP can be associated with or disassociated from a VM instance dynamically.
- A flat EIP can be associated with VM instances created from other flat networks.
Scenarios
- EIP usage in a flat network scenario:
The following diagram shows how an EIP is used in a flat network scenario.
Figure 13. EIP Usage in Flat Network Scenario 
- Public networks can connect to the Internet through firewalls.
- Flat networks provide IP addresses for VM instances in each compute node. Notice that these IP addresses cannot connect to the Internet by default.
- A distributed EIP is deployed on each compute node, and can be associated with public networks or private networks separately.
- EIP usage in a VPC network scenario:
The following diagram shows how an EIP is used in a VPC network scenario.
Figure 14. EIP Usage in VPC Network Scenario 
Considerations
- An instance can have only one EIP associated at a time.
- The EIP association and disassociation operations take effect in real time.
- Associating or disassociating an EIP does not affect the running of an instance.
Port Forwarding
Port forwarding functions based on the layer-3 forwarding service of VPC vRouters. This service forwards traffic flows of the specified IP addresses and ports in a public network to specified ports of VM instances by using the specified protocol. If your public IP addresses are insufficient, you can configure port forwarding for multiple VM instances by using one public IP address and port.
- VM instances in a private network for which SNAT is enabled can access external networks. However, the VM instances in a private network are inaccessible to external networks. You can use a port forwarding rule to allow the access to specified ports of the VM instances from external networks.
- You can associate a port forwarding rule with a VM NIC and disassociate a port forwarding rule from a VM NIC based on your business needs.
- Port forwarding services are provided only by VPC vRouters.Port forwarding rules are applied to a public network associated with a VPC vRouter and a private network where VM instances reside, as shown in the following figure.
Figure 15. Port Forwarding 
- Port forwarding is achieved by using a virtual IP address (VIP).
- A VIP is an available IP address in a public network.
- You can use an existing VIP or create a VIP to provide port forwarding services.
- Two port forwarding methods are supported: port-to-port mapping and port range-based mapping.
Figure 16. VIP-Port Forwarding 
Limits
- The firewall policy of a VM instance must open the port specified for port forwarding.
- The ports used for port forwarding by the same VIP must be unique.
- You can use a VIP to provide port forwarding services for different ports of multiple VM NICs in the same L3 network.
- You can use only one VIP to provide port forwarding services for a VM instance.
- If you disassociate a VIP from a VM instance and then associate the VIP with the VM instance, you can select VM NICs that reside in the same L3 network as the previously disassociated VM instance.
- The source port range and target port range used for port forwarding must be consistent. For example, if you set the source port range to 22-80, the target port range must also be 22-80.
Load Balancing
A load balancer distributes traffic flows of a virtual IP address to backend servers. It automatically inspects the availability of backend servers and isolates unavailable servers during traffic distribution. This way, the load balancer improves the availability and service capability of your business. ZStack Cloud supports multiple NIC teaming for NIC redundancy and load-balancing capabilities.
- Shared-performance load balancing: uses a VPC vRouter to provide load balancing services. Traffic is distributed to backend servers by the VPC vRouter. If the VPC vRouter is providing multiple services, the load balancing service shares the performance of the VPC vRouter with other services.
- Dedicated-performance load balancing: uses a load balancer instance to provide load balancing services. Traffic is distributed to backend servers by the load balancer instance. A load balancer instance is a custom VM instance dedicated to providing load balancing services.
Concepts
- Frontend network: A frontend network is a type of network that is associated
with a load balancer. Requests from the network are distributed by the load balancer
to backend servers based on a specified policy.
- Shared-performance load balancer: You can specify a public network or VPC network as a frontend network.
- Dedicated-performance load balancer: You can specify a public network, flat network, or VPC network as a frontend network.
- Backend network:A backend network is a type of network that is associated
with a load balancer. Requests from frontend networks are distributed by the load
balancer to servers in the backend network.
- Shared-Performance Load Balancer:
- If you specify a public network as the frontend network, you can specify any one of the VPC networks of the VPC vRouter to which the public network is attached as the backend network.
- If you specify a VPC network as the frontend network, you can specify any one of the VPC networks of the VPC vRouter to which the VPC network is attached as the backend network.
- Dedicated-Performance Load Balancer:
- If you specify a public network as the frontend network, you can specify a flat network or any one of the VPC networks of the VPC vRouter to which the public network is attached as the backend network.
- If you specify a flat network as the frontend network, you must specify the same network as the backend network.
- If you specify a VPC network of a VPC vRouter as the frontend network, you must specify the same network as the backend network. If you need to associate the load balancer with more backend networks, you can attach more NICs to the load balancer instance. Note that the backend networks that you associate are among the other VPC networks of the VPC vRouter.
- Shared-Performance Load Balancer:
- Load balancer instance: A load balancer instance is a custom VM instance used to
provide load balancing services.
- The network where the default NIC of a load balancer instance resides is the frontend network of the load balancer instance. The default NIC cannot be detached from a load balancer instance.
- The networks of the NICs of a load balancer instance, except the default NIC, are the backend networks of the load balancer.
- The management NIC (if any) cannot be detached.
- LB image: A dedicated-performance load balancer (LB) image
encapsulates dedicated-performance load-balancing services and can be used to create
load balancer instances. However, a dedicated-performance load balancer image cannot
be used to create VM instances.
- An LB image is a custom image. You can download the image from the Cloud official website and add the image to the platform.
- Load balancer instance: A load balancer (LB) instance offering defines the CPU, memory, image, and management network configuration settings used to create LB instances. LB instances provide load balancing services for the public network, flat network, and VPC network.
- Listener: A listener monitors the frontend requests of a load
balancer and distributes the requests to a backend server based on the specified
policy. In addition, the listener performs health checks on backend
servers.
- Listeners support the TCP, HTTP, HTTPS, and UDP protocols.
- A load balancer can be associated with multiple listeners while a listener can be associated with only one load balancer.
- If the listener uses the weighted round-robin load-balancing algorithm, you can set the weight value for each individual backend server on the backend server group details page.
- Forwarding rule: A forwarding rule forwards the requests from different
domain names or URLs to different backend server groups.
- A forwarding rule is composed of a domain name and URL.
- A listener can have up to 40 forwarding rules.
- You can configure a domain-based or URL-based forwarding rule for a load balancer. You can add multiple forwarding rules to a listener and associate these rules with different backend server groups.
- A forwarding rule is matched by using the exact match and fuzzy match mechanisms. If multiple forwarding rules are matched, the forwarding rule matched through the exact match mechanism is used.
- Certificate: If you select HTTPS for a listener, associate it with a certificate to make the listener take effect. You can upload either a certificate or certificate chain.
- Backend server group: A backend server group is a group of backend servers that
handles requests distributed by load balancers. It is the basic unit for traffic
distribution by load balancer instances.
- A load balancer can be associated with multiple backend server groups, while a backend server group can be associated with only one load balancer.
- A backend server group can be associated with multiple listeners in the same load balancer.
- Creating a load balancer will automatically create an empty backend server group.
- Backend server: A backend server handles requests distributed by a load balancer. You can add a VM instance on the Cloud or a server on a third-party cloud as a backend server.
Certificate
The Certificate feature complies with the digital certificate protocol. Trusted certificate authorities (CAs) issue digital certificates after verifying the identity of a server. The issued certificates can verify server identities and encrypt data transmission.
VPC Firewall
A firewall is an access control policy that monitors ingress and egress traffic of VPC vRouters and decides whether to allow or block specific traffic based on the associated rule sets and rules.
Concepts
- Firewall rule set: A firewall rule set is a set of rules that a firewall uses
to defend against network attacks. You need to associate a rule set with the egress
or ingress flow direction of VPC vRouter NICs to make the rule set take
effect.
- You can associate a rule set with the egress or ingress flow direction
of VPC vRouter NICs:
- Ingress: applies to the traffic that flows into the specified VPC vRouter via a network.
- Egress: applies to the traffic that flows out of the specified VPC vRouter via a network.
- You can associate a rule set with the egress or ingress flow direction
of VPC vRouter NICs:
- Firewall rule: A firewall rule is an access control entry associated with
the egress or ingress flow direction of VPC vRouter NICs to defend against network
attacks. A firewall rule includes rule priority, match condition, and
behavior.
- You can associate a rule with the egress or ingress flow direction of
VPC vRouter NICs:
- Ingress: applies to the traffic that flows into the specified VPC vRouter via a network.
- Egress: applies to the traffic that flows out of the specified VPC vRouter via a network.
- Firewall rules can be categorized into custom rules and system rules:
- Custom rules: rules that you customize. You can select the
ingress or egress direction that the rules take effect and
configure the rule priorities, match conditions, and
behaviors.
- Rule priority: the priority of a rule to be matched and
take effect when compared with other firewall rules.
Valid values: 1001 to 2999.
- Generally, a rule with a higher priority is primarily matched when compared to a rule with a lower priority. Priorities are represented by using numbers. A smaller number indicates a higher priority.
- Generally, the more specific the match condition that you configure for a rule is, the higher priority you shall configure for the rule.
- Match condition: the condition based on which traffic
flowing into or out of a VPC network is matched. It
includes source IP address, destination IP address,
source port, destination port, packet status, and
protocol.
- You can specify one or more source and destination IP addresses. These IP addresses can be static IP addresses, IP ranges, CIDR blocks, or a mix of the three.
- If you specify multiple entries, which include one or more CIDR blocks, the netmask of the CIDR block must be 24. If you specify only one CIDR block, the netmask of the CIDR block is not limited.
- You can enter a maximum of ten entries, with each entry separated by a comma (,).
- Behavior: the action to be applied to traffic that meets
the match condition. Valid values: accept, drop, and
reject.
- Accept: accepts the traffic that flows in or out of the specified VPC vRouter.
- Drop: drops the traffic that flows in or out of the specified VPC vRouter and does not respond to the client.
- Reject: rejects the traffic that flows in or out of the specified VPC vRouter and responds to the client.
- Rule priority: the priority of a rule to be matched and
take effect when compared with other firewall rules.
Valid values: 1001 to 2999.
- System rules: rules predefined to support system services. The
system predefines the direction that the rules take effect, and
the priority, match condition, and behavior of the rules.
- The priority of system rules ranges from 1 to 1000 or from 4000 to 9999.
- ZStack Cloud has predefined the
following system rules:
- Firewall rules that take effect on the ingress
direction of VPC vRouter NICs:
- Rule 1: The priority is 4000, and the behavior and match condition combination determines to allow established or related data packets from any IP address/port, with any protocol, or to any IP address/port, to flow into the specified VPC vRouter via a network.
- Rule 2: The priority is 9999, and the behavior and match condition combination determines to allow new data packets from any IP address/port, with any protocol, or to any IP address/port, to flow into the specified VPC vRouter via a network.
- Rule 3: the default rule with a priority of 10000. The behavior and match condition combination determines to reject data packets from any IP address/port, with any protocol, in any status, or to any IP address/port, from flowing into the specified VPC vRouter via a network. You can modify the behavior of the rule. Valid values: accept, drop, and reject.
- Firewall rules that take effect on the egress
direction of VPC vRouter NICs:
- Rule 1: the default rule with a priority of 10000. The behavior and match condition combination determines to reject data packets from any IP address/port, with any protocol, in any status, or to any IP address/port, from flowing into the specified VPC vRouter via a network. You can modify the behavior of the rule. Valid values: accept, drop, and reject.
- System rules cannot be modified, except the behavior of the default rule.
- System rules cannot be created or deleted.
- Firewall rules that take effect on the ingress
direction of VPC vRouter NICs:
- Custom rules: rules that you customize. You can select the
ingress or egress direction that the rules take effect and
configure the rule priorities, match conditions, and
behaviors.
- You can associate a rule with the egress or ingress flow direction of
VPC vRouter NICs:
- Rule template: A rule template is a template that you can select when you add rules to a rule set or a firewall.
- IP/Port set: An IP or port set is a set of IP addresses or ports that you can select when you add rules to a rule set or a firewall.
Fundamentals
ZStack Cloud allows you to associate rule sets and rules with the ingress and egress direction of VPC vRouter NICs. Then traffics that flow in or out of the VPC vRouter NICs are filtered based on the rule priority, match condition, behavior, and the effect direction. This ensures the security of data communications across VPC networks, of VPC vRouters, and of user business operations.

- When VM-1 attempts to access VM-3: The traffic from VM-1 will match the inbound rule set of the public NIC on the VPC vRouter. If malicious traffics are detected, the access is denied.
- When VM-2 attempts to access VM-4: The traffic from VM-2 will match the inbound rule of the public NIC on the VPC vRouter, and then will match the outbound rule set of the private NIC on the VPC vRouter. If trusted traffics are detected, the access is allowed.
- When Server-2 attempts to access Server-1: The traffic from Sever-2 will match the inbound rule set of the private NIC on the VPC vRouter, and then will match the outbound rule set of the public NIC on the VPC vRouter. If trusted traffics are detected, the access is allowed.
Firewall vs Security
| Item | Security Group | Firewall |
|---|---|---|
| Application scope | VM NIC | The entire VPC network |
| Deployment mode | Distributed | Centralized |
| Deployment location | VM instance | VPC vRouter |
| Configuration policy | Supports only Allow policies | Allows you to customize Accept, Drop, or Reject policies as needed |
| Priority | Takes effect based on the predefined rule sequence | Allows you to customize priorities |
| Match condition | Source IP address, source port, and protocol | Source IP address, source port, destination IP address, destination port, protocol, and packet status |
IPsec Tunnel
An IPSec tunnel encrypts and verifies IP packets that transmit over a virtual private network (VPN) from one site to another.
- IPsec negotiation mode:
For security reasons, we only support the Main mode. The Aggressive mode is not supported.
- IPsec security protocol:
We support only the Encapsulating Security Payload (ESP) protocol.
- IPsec encapsulation mode:
We support the Tunnel mode. The Transport mode is not supported.
- IPsec routing model:
We support only policy-based IPSec VPN. Route-based IPSec VPN is not supported. Therefore, the tunnel supports only unicast data, and does not support multicast and broadcast.
- Prepare two isolated ZStack Cloud and set up two VPC environments in these two clouds respectively. In each VPC environment, create two VPC networks respectively and make sure that these VPC networks cannot communicate with each other. Then, you can use an IPsec tunnel to achieve communication between these VPC networks.
Netflow
A NetFlow monitors the ingress and egress traffic of the NICs of VPC vRouters. The supported versions of data flows are V5 and V9.
Port Mirroring
Port mirroring mirrors the traffic data of VM NICs and sends the traffic data to the target ports. This allows for the analysis of data packets of ports and simplifies the monitoring and management of data traffic and makes it easier to locate network errors and exceptions.
CloudFormation
CloudFormation is a service that simplifies the management of cloud resources and automates deployment and O&S. You can create a stack template to configure cloud resources and their dependencies. This way, resources can be automatically configured and deployed in batches. CloudFormation provides easy management of the lifecycle of cloud resources and integrates automatic O&S into API and SDK.

Characteristics
- You can create a stack template or modify an existing one to define what cloud resources you need, the dependencies between the resources, and the resource configurations. Then CloudFormation automatically uses the orchestration engine to create and configure the resources.
- You can use sample templates and the designer provided by the Cloud to create stack templates. This greatly improves efficiency.
- You can update a stack template as needed. Then you can use the updated template to adjust your resource stacks to accommodate the dynamic changes of your business needs.
- If you no longer need a resource stack, you can delete the stack and all resources in it with one click.
- You can use an existing stack template to quickly duplicate all stack resources and their configuration settings.
- You can flexibly combine cloud services according to your business scenarios to realize the automatic maintenance.
Baremetal Management
ZStack Cloud offers the Baremetal Management service that provides your applications with dedicated physical servers, ensuring the high performance and stability of your key applications. After your servers are configured well and the related preparations are completed, you can deploy baremetal (BM) chassis in bulk on the UI. After the deployment succeeds, you can use these BM chassis to create BM instances. With preconfigured templates, you can achieve unattended batch installation for BM instance operating systems. In addition, you can configure a business network for BM instances and easily manage the entire lifecycle of these BM instances.
The Baremetal Management service is a separate feature module. To use this service, purchase both the Base License and the Plus License of Baremetal Management. The Plus License cannot be used independently.
Basic Workflow
How does the Baremetal Management service work? A deployment server provides two types of service: DHCP and FTP. Specifically, the deployment server can instruct multiple BM chassis to be started through a PXE NIC, and can allocate dynamic IP addresses with the DHCP service. In addition, BM chassis can download related software packages from the deployment server with the FTP service, of whose packages can be applied to the operating system installation of the BM instance, as shown in Baremetal Management Network Topology.

Key Features and Benefits
- Provides applications with dedicated physical servers to ensure the high performance and stability of your key applications.
- Deploy deployment servers independently as recommended, which can meet the requirements for the host high availability scenario of multiple management nodes. This also simplifies the network environment and helps to avoid DHCP conflicts. In addition, you can attach an independent deployment server to each BM cluster, which helps to avoid a single point of failure and improve greatly the deployment rate.
- Helps create BM chassis in bulk on the UI via either the manual creation or template file import. You can also add IPMI addresses in bulk to deploy efficiently BM clusters, which increases O&M efficiencies.
- Helps to quickly generate configuration files by using preconfigured templates to achieve unattended batch installation for BM instance operating systems.
- Enables you to customize the installation of your operating system. Supported operating systems: custom operating system of the Cloud and the mainstream Linux distributions (RHEL/CentOS, Debian/Ubuntu, and SUSE/openSUSE).
- Supports flat network. Specifically, BM instances and VM instances on the same L2 network can reach each other without routing to each other by gateways.
Typical Usage Scenarios
- High-Security and Strict Management Scenario
Financial industry, security industry, and others have rigorous standards for the business compliance and business data security. With the Baremetal Management service, they can ensure their exclusive use of resources, data isolation, strict supervision and control, and effective tracking.
- High-Performance Computing Scenario
In high-performance computing scenarios, supercomputing centers, gene sequencing companies, and other entities require high computing performance, high stability, and accurate real-time update for servers. Sometime later, business performances will be affected by the performance loss and hyper-threading brought by visualization. In this regard, to deploy BM cluster to a certain scale, meet the strict requirements for the high performance computing.
- Key Database Scenario
In some entities, some key database businesses cannot be deployed on normal VM instances, and must be loaded on the physical servers that can protect their exclusive resources, network isolation, and performances. To meet this requirements, use the Baremetal Management service that provides exclusive, high-performance physical servers for one or more appliances.
Baremetal Cluster
- To provide PXE services for baremetal instances on a baremetal cluster, the baremetal cluster must attach a deployment server.
- One baremetal cluster can only attach one deployment server, while one deployment server can attach multiple baremetal clusters simultaneously.
- To provide network services for baremetal instances on a baremetal cluster, the baremetal cluster must attach L2 networks.
- Flat networks are supported. Specifically, both baremetal instances and VM instances on the same L2 network can reach each other without routing via a gateway.
Deployment Server
- We recommend that you deploy PXE servers independently, thus satisfying the need of the multi-MN host HA scenario and avoiding a single point of failure (SPOF) to greatly improve deployment efficiencies.
- A deployment server must be attached to a baremetal cluster.
- One baremetal cluster can only attach one deployment server, while one deployment server can attach multiple baremetal clusters simultaneously.
- A deployment server must have sufficient storage space to save images used for PXE deployments.
- A deployment server must connect to a management network for reaching management nodes.
- A deployment server must connect to a deployment network for reaching baremetal chassis.
- A DHCP listening NIC on a deployment server must connect to a deployment network. In addition, make sure that this deployment network does not contain other DHCP services for avoiding IP conflicts.
- A deployment server must install the latest ZStack Cloud ISO with the recommended h79c version. Otherwise, this deployment server cannot provide software packages for baremetal chassis via the FTP service.
Baremetal Chassis
- A management node must connect to an IPMI network and control remotely baremetal chassis via IPMI.
- A baremetal chassis must contain a BMC interface, and configures an IPMI address, port, user name, and password, to connect to an IPMI network.
- A deployment server-enabled NIC on a baremetal chassis must connect to a deployment network.
- Other NICs of baremetal chassis can connect to the corresponding L2 networks as needed.
Preconfigured Template
- Make sure that you prepare well the preconfigured template in advance on the Cloud.
- A preconfigured template includes the following two types of
templates:
- System template: Is defaulted by the Cloud, including basic system variables, thereby satisfying a simple, unattended deployment scenario.
- Custom template: Enable you to upload custom template files with the UTF8 format. Apart from basic system variables, you can customize other variables as needed to satisfy a complex, unattended deployment scenario.
Baremetal Instance
- A preconfigured template can be used to quickly generate a preconfigured file to install baremetal instance operating systems in bulk without attended interferences.
- Operating system installations can be customized. Currently, the supported versions of operating systems include custom operating systems of the Cloud and mainstream Linux distributions (RHEL/CentOS, Debian/Ubuntu, and SUSE/openSUSE). These versions must be ISO and non-live CD.
- A business network can be configured for baremetal instances. Currently, flat networks are supported. Specifically, both baremetal instances and VM instances on the same L2 network can reach each other without routing via gateways. Make sure that a baremetal cluster where the baremetal chassis resides attaches the corresponding L2 network in advance.
Elastic Baremetal Management
- The Elastic Baremetal Management feature is provided in a separate module. Before you can use this feature, you need to purchase the Plus License of Elastic Baremetal Management, in addition to the Base License.
- A tenant can use an elastic baremetal offering shared by the admin to create an elastic baremetal instance.
Concepts
- Provision network: A provision network is a dedicated network for PXE boot
and image downloads while creating elastic baremetal instances.
- Before you can use Elastic Baremetal Management, you need to deploy an IPv4 provision network.
- Provision networks require high network performance. We recommend that you use at least 10 Gigabit NICs for your provision network.
- You can configure a gateway for your provision network. This way, the provision network can be connected to other networks. If you do not need to connect your provision network to other networks, you do not need to configure a gateway for your provision network.
- Elastic baremetal cluster: An elastic baremetal cluster consists of elastic baremetal
instances. You can manage elastic baremetal instances by managing an elastic
baremetal cluster where the instances reside.
- You must attach a provision network to an elastic baremetal cluster to provide PXE services for baremetal nodes in the cluster.
- You can attach only one provision network to an elastic baremetal cluster. However, you can attach a provision network to multiple elastic baremetal clusters.
- You can attach an L2 network to an elastic baremetal cluster to provide an extended L2 business network for elastic baremetal instances in the cluster. Elastic baremetal instances and VM instances that share the same L2 network can access each other without using the gateway. The L2 network that you can attach to an elastic baremetal cluster can be of the VLAN or NoVLAN type.
- Gateway node: A gateway node is a node where the ingress and egress
traffic of the Cloud and elastic baremetal instances is forwarded.
- You can attach multiple gateway nodes to an elastic baremetal cluster. However, you can attach only one gateway node to an elastic baremetal cluster.
- A gateway node is used to take over primary storages and assign storage space for elastic baremetal instances.
- A gateway node provides iPXE, DHCP, and other services. It is used to deliver configuration settings to elastic baremetal instances.
- Baremetal node: A baremetal node is used to create a baremetal instance
and is identified based on the BMC interface and IPMI configuration
setting.
- You can set the startup methods for the baremetal nodes. The
following two startup methods are supported:
- Startup from a volume: Uses a volume as the system volume of the baremetal node to install and deploy the operating system.
- Startup form a local disk: Uses a local disk as the system volume of the baremetal node to install and deploy the operating system.
- If you select to startup the baremetal node from a local
disk, you can choose whether to take over the original
operating system.
- If you choose not to take over the original operating system, the Local Disk (Non Take-Over) is used. When you use the baremetal node to create an elastic baremetal instance, this method helps download an operating system from the Cloud and install it on the instance. Meanwhile, the local system volume is formatted.
- If you choose to take over the original operating system, the Local Disk (Take-Over) method is used. The elastic baremetal instance created from the baremetal node used the original system operating system stored on the local disk directly.
- The management node must be connected to the IPMI network to remotely manage baremetal nodes.
- Baremetal nodes must be configured with the BMC interfaces, IPMI addresses, ports, usernames, and passwords, and be connected to the IPMI network.
- A baremetal node can be distributed to only one elastic baremetal instance and an elastic baremetal instance can only be assigned one baremetal node.
- You can provide compute resources for elastic baremetal instances by using a baremetal node or elastic baremetal offering.
- You can set the startup methods for the baremetal nodes. The
following two startup methods are supported:
- Elastic baremetal instance offering: An elastic baremetal offering defines the number of vCPU
cores, memory size, CPU architecture, CPU model, and other configuration settings of
elastic baremetal instances.
- You can get elastic baremetal offerings of baremetal nodes by obtaining their hardware information. Baremetal nodes with the same offering can be managed in a unified way.
- The baremetal offerings obtained from the node hardware information can be classified into 3 types according to their startup methods: startup from a volume, startup from a local disk (take-over), and startup from a local disk (non take-over).
- You can use an elastic baremetal offering to create an elastic baremetal instance. You can also release the advanced settings of baremetal nodes to avoid resource idling.
- You can create a pricing list for elastic baremetal instances based on elastic baremetal offerings. Then bills are generated for the elastic baremetal instances based on their usage.
- Elastic baremetal instance: An elastic baremetal instance has the same performance as
physical servers and allows elastic scaling. You can apply for and scale resources
based on your needs.
- The following two startup methods are supported for elastic
baremetal instances:
- Volume: Uses a volume as the system volume of the elastic baremetal instance to install and deploy the operating system.
- Local Disk: Uses a local disk as the system disk of the elastic baremetal instance to install and deploy the operating system.
- The Local Disk (Non Take-Over) and Local Disk (Take-Over)
methods are supported:
- Local Disk (Non Take-Over): When you use a baremetal node to create the elastic baremetal instance, the operating system is downloaded from the Cloud and installed on the elastic baremetal instance. This method will format the local system disk.
- Local Disk (Take-Over): When you use a baremetal node to create the elastic baremetal instance, the original operating system on the local system disk is used as the operating system of the elastic baremetal instance.
- The following describes the resources supplied to elastic baremetal
instances of different startup methods:
- To elastic baremetal instances of both the volume startup method and local disk startup method, the compute resources are provided by corresponding baremetal nodes, and L3 networks on the Cloud are used as their business networks.
- To elastic baremetal instances of the volume startup method, the storage resources are provided by SharedBlock or Ceph primary storage on the Cloud, and the PXE boots are supported by the provision network.
- To elastic baremetal instances of local disk startup method, the storage resources are provides by their local disks. If you attach data volumes to the instances, they can use the storage resources provided by SharedBlock or Ceph primary storage on the Cloud.
- We recommend that you create an elastic baremetal instance by using an image that has installed the agent. Otherwise, you cannot perform the following actions on the instance: open the instance console, modify the instance password, attach a volume to or detach a volume from the instance, and attach a network to or detach a network from the instance.
- By default, you can you an image whose BIOS mode is UEFI to create an elastic baremetal instance. If you need to use an image with a Legacy BIOS mode, contact the official technical support.
- You can configure business networks for elastic baremetal instances. If you attach an L2 network to the cluster where your baremetal nodes reside, elastic baremetal instances and VM instances that share the same L2 network can access each other without using the gateway.
- You can enable the elastic baremetal instances of the volume startup method to automatically release the associated baremetal node when it is powered-off. The baremetal node released can be used by other elastic baremetal instances, thus avoiding the resource idling.
- The following two startup methods are supported for elastic
baremetal instances:
Scenarios
- Scenarios that require high security and strict monitoring:
The financial and insurance industries have high requirements over business deployment compliance and data security. In these scenarios, you can use Baremetal Management to secure dedicated resources, data isolation, easy management, and operation-tracking. This way, you can ensure the reliability and security compliance of your key business system and data.
- High-performance computing scenarios:
Supercomputing, genome sequencing, and other high-performance computing scenarios have high requirements over the computing performance, stability, and timeliness. However, the virtualization may cause performance losses and hyperthreading may negatively influence the business. Deploying a reasonable number of baremetal clusters can solve these problems, meeting the high-performance computing requirements.
- Key database scenarios:
To meet business requirements, you may not want to deploy some key databases on VM instances while want to deploy the databases on physical servers that feature dedicated resources, network isolation, and guaranteed performance. In these scenarios, you can use Baremetal Management to provide dedicated high-performance physical servers for your applications.
Advantages
- Integration of high performance and scalability:
Elastic Baremetal Management provides dedicated physical servers for your applications to ensure high performance and stability. In addition, this feature allows elastic scaling. You can apply for and scale resources based on your needs.
- Strong scalability:
A single management node allows you to manage 10,000 baremetal nodes and scale-out according to your needs.
- Strong compatibility:
An elastic baremetal instance no longer depends on IPMI/BMC network (optional), and the NIC can be used as a baremetal node as long as it supports PXE boot. The realization of the elastic baremetal instance does not associate any CPU or virtualization technology. As long as there is a system image that can be started, and no matter if it is an ISO, qcow2, or raw image, it can be used as a virtual hard disk by an elastic baremetal instance. That is, the elastic baremetal can be directly used on domestic servers.
In addition, the elastic baremetal management feature can be achieved by software only, without purchasing any proprietary hardware. It is compatible with all x86 and most of domestic ARM CPU architectures and supports mainstream x86 operating systems and some ARM operating systems.
- Advanced technology:
In addition to turn on/off baremetal servers and deploy system, elastic baremetal management also supports the use of virtual resources on the Cloud, including VPC/flat/public networks, volumes, primary storage and other resources, which seamlessly connects physical resources and cloud resources, and greatly improves the availability of cloud resources.
- Consistency in operation experience:
All features of a VM instance can be directly operated on an elastic baremetal instance. And an elastic baremetal instance can use any advanced network services without purchasing additional network hardware.
- Flexible deployment:
An elastic baremetal instance supports both volume deployment method and local disk deployment method, respectively using the primary storage resource and the local disk on the Cloud, which combines the scalability of resources on the Cloud with the stable I/O and high throughput of local disks.
The primary storage resources used by an elastic baremetal instance can be shared by the KVM clusters of the Cloud, which relieves you from deploying additional storage resources. In addition, local disk deployment method supports take over the original system, which effectively ensures the business continuity.
VMware Management
Introduction
VMware Management manipulates VMware vCenter via VMware public APIs and seamlessly integrates some features of VMware vCenter Server to achieve a unified management of multiple virtualization platforms on ZStack Cloud. If you deployed a VMware vCenter Server, you can use VMware Management of ZStack Cloud to take over the VMware vCenter Server. Then you can view vSphere servers and virtual machines managed by the VMware vCenter Server, use VMware vSphere resources in the virtual data center, and perform operations on virtual machines in the VMware vCenter clusters.
- The VMware Management feature is provided in a separate module. Before you can use this feature, you need to purchase the Plus License of VMware Management, in addition to the Base License.
- ZStack Cloud supports multiple vCenter versions, including 5.5, 6.0, 6.5, 6.7, and 7.0.
Basic Resource
ZStack Cloud can manage vCenter basic resources in a unified manner. In ZStack Cloud, you can add a vCenter, synchronize data for a vCenter, and delete a vCenter.
- You can add and manage multiple vCenters.
- You can filter resources before you import vCenter resources to ZStack Cloud.
- dvSwitch scenario:
Only resources of the hosts that are added to a dvSwitch can be imported to ZStack Cloud. If you do not add a host to a dvSwitch, the associated resources cannot be imported to ZStack Cloud.
- vSwitch scenario:The resources imported to ZStack Cloud must be the resources of the hosts in the same cluster and must be added with at least one same vSwitch name. In addition, they must have at least one same port group attribute (including the same network labels and the same VLAN ID) at the same time.
Note: ZStack Cloud can only manage VM networks
rather than VMkernels or management
networks.
- dvSwitch scenario:
VM Instance
After you add a vCenter, VM instances in the vCenter will be automatically synchronized to ZStack Cloud. You can also create vCenter VM instances on your Cloud.
Network
Before you can create new VM instances in the vCenter managed by ZStack Cloud, create a VPC network or a flat network in the vCenter in advance.
vCenter network service currently supports the VPC network architecture model.
- SNAT: A VPC vRouter provides the source network address translation (SNAT) service to vCenter VM instances. vCenter VM instances can directly access the Internet by using SNAT.
- DHCP: Centralized DHCP services realize a dynamic IP address obtainment.
- EIP: Allows a VPC vRouter to access the private network of a vCenter VM instance through a public network.
- Port forwarding: Forwards the port traffics of a specified public IP address to the port of a corresponding vCenter VM IP address.
- Load balancing: Distributes inbound traffics from a public IP address to a group of backend vCenter VM instances, and then automatically detects and isolates unavailable vCenter VM instances.
- IPsec tunnel: Uses an IPsec tunnel protocol to provide site-to-site VPN connections.
Network Service
- SNAT: A VPC vRouter provides the source network address translation (SNAT) service to vCenter VM instances. vCenter VM instances can directly access the Internet by using SNAT.
- DHCP: Centralized DHCP services realize a dynamic IP address obtainment.
- EIP: Allows a VPC vRouter to access the private network of a vCenter VM instance through a public network.
- Port forwarding: Forwards the port traffics of a specified public IP address to the port of a corresponding vCenter VM IP address.
- Load balancing: Distributes inbound traffics from a public IP address to a group of backend vCenter VM instances, and then automatically detects and isolates unavailable vCenter VM instances.
- IPsec tunnel: Uses an IPsec tunnel protocol to provide site-to-site VPN connections.
ZStack Cloud supports multi-account management in a managed vCenter. Normal accounts and project members can use vCenter network services, including EIP, port forwarding, and load balancing.
Volume
- Root volume: A system volume of the VM instance. The root volume supports the system operation of a VM instance.
- Data Volume: A data volume used for the VM instance. The data volume provides extended storage space for a VM instance.
Volume management in vCenter mainly involves data volumes.。
Image
In ZStack Cloud, you can add a local image of the VMDK format to a vCenter. Then, you can synchronize the vCenter image between the local client and the remote client by synchronizing data. Both system images and volume images can be added.
Event Message
- The UI can display up to 300 event messages. You can set a time range to check alarm messages within the time range via the time adjustment button at the upper left.
- You can choose to display alarm message count for each page via display count button at the lower right. Optional value: 10, 20, 50, and 100. You can turn pages by clicking the left/right arrow button.
Hybrid Cloud Management
Alibaba Cloud Hybrid Cloud Management provided by ZStack Cloud integrates the simple, strong, scalable, and smart (4S) features of ZStack Cloud Private Cloud and the advanced, secure, and stable features of Alibaba Cloud Public Cloud. It is a hybrid cloud management solution that seamlessly integrates cloud services and terminals, interconnecting the control panel and data panel.
Concepts
- ZStack Cloud Alibaba Cloud Hybrid Cloud Management
provides the following cloud computing products of Alibaba Cloud:
- ECS Instance: An elastic compute service (ECS) instance is a VM instance created on Alibaba Cloud.
- Disk: A disk provides storage space for an ECS instance created on Alibaba Cloud.
- Image: An image is a template file that is used to create ECS instances. Images are categorized into custom images and Alibaba Cloud images.
- Security Group: A security group provides security control services for ECS instances on the L3 network. It filters the inbound or outbound packets of ECS instances based on security rules.
- VPC: A virtual private cloud (VPC) is a private network dedicated for ECS instances created on Alibaba Cloud.
- EIP: An elastic IP address (EIP) is an IP address in Alibaba Cloud public networks. You can attach EIPs to ECS instances so that the ECS instances can access public networks by using the EIPs.
- VPN: Establishes a site-to-site IPsec VPN channel to enable communications
between private networks in a local data center and Alibaba Cloud VPC. This
section includes:
- VPN Gateway: A virtual private network (VPN) gateway establishes a secure connection between a local data center and Alibaba Cloud VPC by using an encrypted channel.
- VPN Customer Gateway: A VPN customer gateway provides services for a local data center.
- VPN Connection: A VPN connection is an encrypted communication channel established between a VPN gateway and VPN customer gateway.
- Express Connect: Express Connect uses physical circuits (electric cables or
optical fibers leased from operators) to connect local data centers with
Alibaba Cloud access points and Alibaba Cloud VPC. This way, private
networks on Alibaba Cloud and in local data centers can communicate with
each other in a fast, stable, and secure manner. This section includes:
- Router Interface: A router interface is a virtual device that is used to establish communication channels and control their status.
- Virtual Border Router: A virtual border router (VBR) is virtualized from a physical switch port on the access point of Alibaba Cloud. It forwards the data on the physical circuit to Alibaba Cloud VPC.
- Alibaba Cloud NAS: Alibaba Cloud NAS is a network-attached file storage
service. It provides highly reliable and available distributed file systems
that can be accessed by using standard file access protocols. In addition,
Alibaba Cloud NAS is scalable in storage space and performance and can be
managed in a namespace while shared with multiple users. ZStack Cloud seamlessly integrates with Alibaba Cloud NAS.
You can add primary storage of the AliyunNAS type on ZStack Cloud
Private Cloud so as to use the distributed
storage independently deployed on Alibaba Cloud. This section includes:
- File System: A file system is a backend storage system used for Alibaba Cloud NAS primary storage. Before you add an AliyunNAS primary storage, you need to add an NAS file system.
- Permission Group: A permission group is an allowlist of IP addresses or IP ranges which can access file systems according to specified permission rules.
- Data Center: Data centers are resources corresponding to Alibaba Cloud
regions and zones. These resources include:
- Region: A region is a physical data center. A region in ZStack Cloud Hybrid Cloud corresponds to a region in Alibaba Cloud.
- Zone: A zone is a physical area in a region that is independent from other zones in the region in terms of electricity and network supplies.
- Setting: ZStack Cloud Hybrid Cloud provides the
following basic settings:
- AccessKey Management: An AccessKey pair is an identity credential that has access to APIs of Alibaba Cloud or Private Alibaba Cloud. It has full access to the Cloud. An AccessKey pair consists of AccessKey ID and AccessKey secret.
- Hybrid Cloud Settings: Hybrid cloud settings allow you to configure settings that take effect on the whole platform.
Physical Deployment
ZStack Cloud Hybrid Cloud uses an in-process micro-service architecture and does not introduce a new module. ZStack Cloud management nodes need to access the Internet so that they can call Alibaba Cloud Public Cloud APIs.

Architecture
ZStack Cloud Hybrid Cloud includes the following sections:
- Identity Authentication:Alibaba Cloud AccessKey: integrates Resource Access Management of Alibaba Cloud Public Cloud / Private Cloud. A user authorized with an Alibaba Cloud AccessKey pair can access remote resources on Alibaba Cloud.
Figure 21. Identity Authentication 
- Network Interconnection:
You can use IPsec tunnels or Alibaba Cloud Express Connect to connect local Private Cloud with Alibaba Cloud Public Cloud. This way, local-remote L3 networks can access each other. The Local-remote network interconnection is the foundation of ZStack Cloud Hybrid Cloud.
ZStack Cloud Hybrid Cloud allows you to use IPsec tunnels or Alibaba Cloud Express Connect to establish interconnected networks.Figure 22. IPsec Tunnel 
Figure 23. Alibaba Cloud Express Connect 
- Resource Management:You can authorize a RAM user to manage Alibaba Cloud Public Cloud resources, including ECS instances, VBR, VPC, and virtual switches.
Resource Management

- Business Implementation:
The identity authentication, network interconnection, and resource management mechanisms help establish a flexible and elastic business system architecture. After the hybrid cloud platform is established, you can deploy flexible and multi-dimensional business modes on it.
Characteristics
- Seamless integration:
ZStack Cloud Hybrid Cloud seamlessly integrates Alibaba Cloud Public Cloud. Combined with the benefits of ZStack Cloud Private Cloud, it provides users a platform to manage both public clouds and private clouds in a unified way.
- Seamless upgrading:
ZStack Cloud Hybrid Cloud allows seamless upgrading without affecting business continuity.
- Easy to use:
ZStack Cloud Hybrid Cloud seamlessly integrates cloud services and terminals in a unified cloud platform. You can easily manage local private clouds and access resources on the public cloud as needed.
Scenarios
- Data backup on the Cloud
Financial, medical and some other industries have a high requirement for the compliance of long-term data storage. However, backing up data in local data centers is relatively risky, cost-consuming, and hard for O&M. To deal with these problems, ZStack Cloud Hybrid Cloud helps you back up the data to the Cloud, providing you with a stable data storage service at a lower cost.
- Data storage on Cloud
Enterprises and institutions need to store large amounts of data. In these scenarios, you can use ZStack Cloud Hybrid Cloud to store data on Cloud. This solution lowers your investment and management costs and allows data access from multiple regions and zones.
- Data migration on Cloud
High data negotiability is important to some enterprises and institutions whose works are finished based on multi-regional cooperation. In these scenarios, you can use ZStack Cloud Hybrid Cloud to migrate data to Cloud, thus ensuring a stable data transmission and data integrity.
