Zerto has identified a compatibility issue relating to certain storage management products that can lead to unexpected behavior.
What is the issue?
On February 28, 2017 Zerto communicated a ZVR compatibility issue with Nutanix IO Control feature and worked swiftly to resolve this with known impacted customers. Zerto now suspects that the issue could potentially occur in non-Nutanix environments. It is important to note that ZVR is not corrupting the data, rather ZVR was incorrectly handling the failure code generated. Due to the non-standard formatting, older versions of Zerto do not handle these error messages correctly. The result is that, in the case of a failed IO, the error code is mishandled, causing the protected VM to believe the IO was successful, when it was not. If this occurs, data corruption could occur in protected virtual machines on the protected site. It is important to note that ZVR is not corrupting the data, rather the ZVR was incorrectly handling the failure code.
This condition takes place when a storage array controller fails or is nonresponsive due to an upgrade, maintenance activity, or network connectivity issues. It is not expected to happen under normal operating conditions. Because we cannot know the universe of Arrays that utilize the non-standard error code in VMWare ESXi, we recommend customers upgrade to the versions of Zerto Virtual Replication cited below.
What is the resolution?
Zerto released ZVR version 5.0u2, containing updated host components which fix the handling of the error messages. In the case where customers can not move from 4.5, Zerto has released 4.5u5p1, which also contains the host component update.
- NOTE: Upgrading to 5.0u2 from any 4.5 version will incur a delta sync
- NOTE: Upgrading to 5.0u2 from any 5.0 version will NOT incur a delta sync
- NOTE: Upgrading to 4.5u5p1 from any previous version of ZVR will incur a delta sync
How to obtain
The new versions can be obtained through the Support & Downloads section after logging into www.zerto.com/myzerto. Once the Zerto Virtual Manager has been updated, it will be necessary to upgrade the Virtual Replication Appliances (VRA's) through the Setup tab of the ZVM interface. This will update the host component with the fixed code, preventing the issue from occurring in the future.
If you need assistance with the upgrade procedure, please contact Zerto Support.