1. 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 image storage on the same management node.
   • Allows you to obtain the existing image files under the URL path in the image storage.
2. 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 image storage.
     • You can export images, copy exported image URLs, and download exported images on the UI.
     • You can also export images on an image storage.

       For example, assume that the image path you use is ceph://bak-t-c9923f9821bf45498fdf9cdfa1749943/61ece0adc7244b0cbd12dafbc5494f0c.

       Then, run the following command on the image 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.

3. 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 image storage. For more information, contact the official technical support.

• When primary storage are LocalStorage, NFS, or SMP, the default type for image 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 image storage. In this regard, both primary storage and image storage can use the network shared storage.
• When primary storage is Ceph, you can use the primary storage in the same Ceph cluster as image storage. You can also use the ImageStore primary storage as image storage.
• When primary storage is SharedBlock, the default type for image storage is ImageStore.
• When primary storage is AliyunNAS, the default type for image storage is ImageStore.
• When primary storage is AliyunEBS, the default type for image storage is AliyunEBS.

{
  "inventories": [
    {
      "uuid": "31cbc4dad8da3ca6a6e3df5c1d5f233e",
      "name": "test"
    }
  ]
}

totalCapacity = backup storage's total capacity
availableCapacity = totalCapacity - sum (images' actual sizes)

• Enabled:

  Indicates that images can be registered, backed up, and downloaded.

• Disabled:

  Indicates that images cannot be registered, backed up, or downloaded. Especially, if an image is only stored on a disabled backup storage, and if the image is not downloaded to image caches of primary storage, this image cannot be used to create VM instances.

• Connecting:

  Indicates that a ZStack Cloud management node is trying to establish a command channel between the node itself and a backup storage. At this stage, you cannot perform any operation on the backup storage.

• Connected:

  Indicates that the command channel between a ZStack Cloud management node and a backup storage is established successfully. At this stage, you can perform related operations on the backup storage.

• Disconnected:

  Indicates that the command channel between a ZStack Cloud management node and a backup storage is lost. At this stage, you cannot perform any operation on the backup storage.