Issue related to VMware KB 2136854 causes inconsistent incremental VM backups

Content

Tip: Beginning with Version 7.1.3, IBM Tivoli Storage Manager is now IBM Spectrum Protect™ and IBM Tivoli Storage FlashCopy Manager is now IBM Spectrum Protect™ Snapshot. Some applications such as the software fulfillment systems and IBM License Metric Tool use the new product names. However, the software and product documentation continue to use the Tivoli Storage Manager (TSM) and FlashCopy Manager (FCM) product names. To learn more about the rebranding transition, see http://www.ibm.com/support/docview.wss?uid=swg21963634.

According to VMware Knowledge Base publication 2136854, the VMware QueryDiskChangedAreas() API call used to obtain changed block information can omit sectors which have changed during snapshot consolidation, resulting in inconsistent incremental virtual machine (VM) backups using ESXi 6.0 hosts. The IBM Tivoli Storage Manager for Virtual Environments (TSM for VE): Data Protection for VMware (DP for VMware) and IBM Spectrum Protect: DP for VMware incremental backups call this VMware API, and are dependent upon on its data to perform incremental backups. No indication or error message is provided by the VMware API to TSM for VE or IBM Spectrum Protect for VE or to the user when this issue occurs.

The VMware QueryDiskChangedAreas() API is not used by IBM Tivoli Storage FlashCopy Manager for VMware and IBM Spectrum Protect Snapshot for VMware for regular operations, but offloaded backups to the TSM Server can be affected because these backups use the DP for VMware data mover, which does call that API. FCM for VMware and IBM Spectrum Protect Snapshot for VMware ESXi 6.0 customers need to follow the steps in the Fix section below for offloaded backups to TSM.

FIX

Summary

According to VMware's KB article 2136854:

• this issue is resolved in VMware ESXi 6.0 patch ESXi600-201511001
• after the patch has been applied, a full reset of the CBT for certain virtual machines might be required
• a full virtual machine backup must be created to ensure incremental virtual machine backup integrity

1. Refer to VMware Knowledge Base article 2136854 (http://kb.vmware.com/kb/2136854) for details about this issue, information about obtaining the VMware ESXi 6.0 patch, and information about identifying virtual machines for which a CBT reset is required.

2. Apply the VMware ESXi patch.

3. Reset CBT for those virtual machines that require a CBT reset.

4. Perform a full backup of all virtual machines. For machines whose CBT was not reset, use the -mode=iffull option with the backup vm command. For those machines whose CBT was reset, -mode=iffull can also be used, but is not required, since the CBT reset will automatically trigger a full VM backup.

5. After the full backups have finished, resume normal incremental forever backup operations.