AhsayCBS (DIY)Hyper-V Cluster backup fails: CBT log mismatch with VM owners
May 16, 2025
Product Version
AhsayOBM: Pre-7.15.4.10
Operating System
Windows
Symptom
When performing a Hyper-V cluster VM backup, the following warning message is displayed on the backup client interface, or in the backup report:
| No. | Type | Timestamp | Log |
| * | ... | ... | ... |
| * | info | ... | Start to collect CBT logs. |
| * | warn | YYYY/MM/DD hh:mm:ss | Unable to generate delta using CBT. Reason = "The number of CBT log files do not match the number of virtual machine's preferred owners." (ClusterStorage\Machine_Name\ VIRTUAL HARD DISKS\Machine_Name.VHDX) |
| * | ... | ... | ... |
Cause
This is a known issue with AhsayOBM version pre-7.15.4.10.
Resolution
To resolve the issue, patch the AhsayOBM application to version 7.15.4.10 or above.
This issue affects a legacy version of our software. We strongly recommend upgrading to the latest AhsayCBS and AhsayOBM release (v9.15.0.0, as of 2025/May/15) for improved performance, compatibility, and security.
Contact us to confirm your license is valid to upgrade.