Full Restore Point Generated by Veeam Agent for Microsoft Windows Cluster Backup Is Larger Than Source Cluster
Challenge
The Backup Job for a Failover Cluster, or its associated Backup Copy Job, generates full (.vbk) restore points that are larger than the source Failover Cluster.
Cause
During the cluster backup, Veeam Agent for Microsoft Windows will duplicate the blocks within shared disks. However, if the cluster disk(s) size is greater than 64 TiB, some blocks may not be deduplicated, causing the restore point to be substantially larger than the source.
Solution
Potential Performance Impact
In rare circumstances configuring the DedupeIndexLimit to such a high value may reduce backup performance. You may contact Veeam support before proceeding with these steps, and we can assist with evaluating whether this is likely to happen, or you may proceed and create a support case should any performance issue occur.
- Create the following registry value on the machine where the target VeeamAgent process operates.
Key Location: HKLM\SOFTWARE\Veeam\Veeam Backup and Replication
Value Name: DedupeIndexLimit
Value Type: DWORD (32-bit) Value
Value Data(Dec): 16777216
Default value is 8388608- For Windows repositories, the target VeeamAgent process operates on the Windows machine itself.
- For NFS and SMB repositories, you should assign a dedicated Gateway server and create the registry value on that machine.
- For Linux repositories, this setting is controlled by creating the file /etc/VeeamAgentConfig and adding the following entry to it:
DedupeIndexLimit=16777216
- Within Backup Job for the Failover Cluster, ensure that the Storage Optimization (block size) has been set to 4MB.
- Force the Backup Job for the Failover Cluster to perform an Active Full.
More Information
If you have any questions or concerns, please create a support case for assistance.
To submit feedback regarding this article, please click this link: Send Article Feedback
To report a typo on this page, highlight the typo with your mouse and press CTRL + Enter.
To report a typo on this page, highlight the typo with your mouse and press CTRL + Enter.