We have recently confirmed a critical issue related to virtual machine backups:

• On Hyper-V 2008 R2/2012/2012 R2, due to a bug with the CBT (Change Block Tracking) filter.
• On Hyper-V 2016, due to bug in the handling of RCT (Resilient Change Tracking) data.

Because of these issues, the change tracking data is no longer reliable for incremental backups. All Hyper-V virtual machines backups taken using AhsayOBM v8.3.2.11 are no longer restorable.

• AhsayOBM v8.3.2.11 to v8.3.2.139

• Hyper-V 2008 R2
• Hyper-V 2012 and 2012 R2
• Hyper-V 2016

Partners are strongly advised to immediately:

1. Upgrade all affected clients to AhsayOBM v8.3.6.30 or above.
2. After upgrading to AhsayOBM v8.3.6.30 or above, if in-file delta is enabled on the backup set. The first backup job run a mandatory differential backup job.

If your current version is not AhsayCBS v8.3.6.30 or above, then upgrade your AhsayCBS to the latest version first. Please refer to these KB article for upgrade instructions:

• Windows/Linux/FreeBSD
• AhsayUBS

Stop! Do not upgrade until you contact a member our Sales team sales-kb@ahsay.com for assistance with your maintenance renewal.

Our professional service team is ready to provide immediate assistance to partners with AhsayCBS v8 upgrades.

Please contact a member our Sales team sales-kb@ahsay.com to obtain a quotation for the AhsayCBS upgrade service.