ZStack ZStone 5.5.6
In July 2026, ZStack ZStone officially released version ZStack ZStone 5.5.6. This release introduces several major features, as described below.
Release Overview
- High-performance storage pools support two replicas and replica switching
- Select two replicas when creating a high-performance storage pool
- Switch between two and three replicas
- Delete an empty high-performance storage cluster
- Read-only access when the license is abnormal or expired
Storage Resource
High-Performance Storage Pools Support Two Replicas and Replica Switching
Starting with ZStack ZStone 5.5.6, high-performance storage pools support two replicas. You can also switch an existing high-performance storage pool between two and three replicas. This enables you to select and adjust the number of replicas based on service requirements for data reliability and storage utilization.
Create a High-Performance Storage Pool with Two Replicas
When creating a high-performance storage pool, you can select two or three replicas based on your service requirements. The default value is three replicas. Compared with three replicas, two replicas reduce data redundancy overhead and improve storage utilization.
Note: In two-replica mode, two copies of the data are stored. However, at least three
logical failure domains (nodes) are still required to ensure Raft consistency. One
node acts as a witness that participates in voting but does not store a complete
copy of the data.Switch Between Two and Three Replicas
For an existing high-performance storage pool in the Healthy state, you can select Modify Data Security Policy on the storage pool list to change the number of replicas from two to three or from three to two.
Changing the number of replicas triggers data migration. During the switch, the storage pool state changes to Recovering and returns to Healthy after data migration is complete. Data migration may affect service performance. Perform this operation outside of peak business hours.
After the switch is complete, you can expand or reduce the high-performance storage pool based on the current replica policy. The platform verifies that the remaining data disks and logical failure domains meet the requirements of the current number of replicas, preventing the operation from degrading the storage pool.
Hardware
Delete an Empty High-Performance Storage Cluster
Starting with ZStack ZStone 5.5.6, a Delete action is available on the high-performance storage cluster list under . If a high-performance storage cluster contains no servers, you can delete the cluster directly from the UI.
If servers remain in the cluster, the platform disables the delete action and prompts you to remove the servers first. Deleting a cluster removes its configuration information and cannot be undone. Before proceeding, you must confirm the risks and complete login password verification.
This feature allows you to clean up high-performance storage clusters that were not fully initialized or whose servers have all been removed, making it easier to replan and reinitialize the high-performance storage environment.
License Management
Read-Only Access When the License Is Abnormal or Expired
ZStack ZStone 5.5.6 optimizes access control when a license is abnormal or expired. When the license status is Abnormal or Expired, you can still access the ZStack ZStone UI, browse feature pages, and view resource lists, resource details, and runtime status.
When the license is abnormal or expired, the platform enters read-only mode. You can only perform query and browse operations. Operations that change platform configuration or resource status, such as creating, modifying, or deleting resources and handling alarms, are not available. If you attempt such an operation, the platform rejects the request and prompts you to check the license status.
By retaining read-only access, the platform allows you to continue monitoring cluster and storage resource status while the license is unavailable, helping you troubleshoot the issue and restore authorization.