Open registry editor with administrative privileges (regedit.exe) on the mount server and create the following keys and values if they have not been added already. Mount server name could be found in the repository settings where verified VM is saved. Increase the timeouts to 2x or 3x the default value. Although, you can increase the timeouts beyond these limits, it is usually better to investigate performance first. Make sure no jobs or restore are running, then restart the Veeam Backup Service to apply these changes.
Key: HKLM\SOFTWARE\Veeam\Veeam Backup and Replication\SureBackup
Default value: 600 (seconds)
Suggested value: 1800
Key: HKLM\SOFTWARE\Veeam\Veeam Backup and Replication
Default value: 900 (seconds)
Suggested value: 1800
The most common cause of this error is slow read performance from the backup repository. Deduplicating storage is not recommended as a back-end for Surebackup. If you must verify backups from deduplicating storage, it may be necessary to increase the above timeouts to several hours, especially if there are any large (multi-TB) VM disks. Where possible, optimize storage devices for random read I/O of large blocks (typically 256 KB – 512KB with default settings, or 4 MB for backups on deduplicating storage; your use case may vary). A simple benchmark is described in KB2014.
As a workaround, or to verify that storage performance is the cause of the timeout, try temporarily moving the backup files to faster storage.
Additional performance troubleshooting:
- If performing verification of offsite backups, make sure the virtual lab and vPower NFS server are located in the same site as the repository.
- Depending on the underlying infrastructure, there can be significant performance differences between running the vPower NFS service from a VM or from a physical machine. For example, try using a VM located on the same ESXi host as the virtual lab.
- Heavily fragmented full backup files can reduce restore performance. Schedule compact operations to reduce fragmentation.
- Where applicable, test throughput of the network connections between the repository and vPower NFS server, and between the vPower NFS server and the ESXi host.
- Investigate CPU and memory usage of the repository and vPower servers.