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Miscellaneous operations
27 Dell EMC SC Series: Veeam Backup & Replication Integration | 4061-SC-SG
As mentioned above, the rescan process evaluates every snapshot on a volume. The amount of time it takes
to rescan a volume is fairly linear with the number of snapshots on a volume. In the example below, note the
time required to scan the volume on the left with 9 snapshots and the volume on the right with 73 snapshots.
There are a variety of reasons to manage and limit the number of snapshots a volume has, and Veeam
Backup & Replication is an addition reason. As an alternative, the earlier section on volume filtering provides
a method to eliminate volumes completely from the rescan process. Veeam documentation refers to this
process as limiting the rescan scope. One example takes another look at the two volumes above. If the right-
hand volume is not used by Veeam Backup & Replication, 12-minute rescans performed every 10 minutes
can be eliminated by filtering out that volume.
Note: In environments where both iSCSI and Fibre Channel storage fabrics are available, iSCSI will be
preferred for the scan process as it is faster.
For large environments, two Windows registry entries on the Veeam backup server can be used to tune the
automatic rescan interval frequency.
Path: HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and Replication
Key: SanMonitorTimeout
Type: REG_DWORD
Default value: 600 (seconds)
Description: Defines incremental rescan interval in seconds
Path: HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and Replication
Key: SanRescan_Periodically_Days
Type: REG_DWORD
Default value: 7 (days)
Description: Defines periodic full rescan interval in days