How to Check Which Volume is Causing the Error (Server OS Only)
In some cases, it may not be obvious which volume needs to be modified. To isolate the problem, perform the following steps within the VM guest OS that cannot be backed up or replicated.
Note: Intermitent errors may be caused by heavy load occuring at specific times, manual testing as shown here may provide false positives if the same heavy load is not occuring.
Using Shadow Copies Utility
Create and then delete a shadow copy of each volume, one at a time. To access the GUI, right click any volume and choose Configure Shadow Copies. On older operating systems, this may instead be a tab in Properties. In the Shadow Copies utility:
- Select a volume.
- Click Create Now.
- If this is successful, select the shadow copy and click Delete Now.
- Repeat steps 1-3 for each volume.
Using Diskshadow Utility
This can also be performed using the Diskshadow utility, which may provide a better match for the behavior of the VSS API used by Veeam Backup & Replication. See, KB1980: Using the Diskshadow Utility to Manually Test VSS Operations
If the affected volume has sufficient free disk space, the shadow storage limit may be too small. Redirect the shadow copies as shown above, or increase the shadow storage limit.