Use Case:
When a backup is in progress, the pre-defined VSS usage percentage is overwritten by the software in order to complete the backup at a proper pace. For example, if VSS usage is limited to 10%, it will be set to 100% during the backup and back down to 10% after the backup is complete.
Symptoms:
VSS Usage percentage is not set back to pre-defined value after backup.
Root Cause:
This issue is commonly caused by a backup being interrupted. Running a successful backup may not revert the value back to the default set previously, as the value when this backup starts is still at 100%.
Solution:
1. Manually re-adjust the VSS usage percent if a backup is interrupted and the value remains at 100%.
2. Development team is tracking this issue and a fix will be introduced in future versions.
Workaround:
If backups are prone to being interrupted and this issue happens frequently, you can set the following parameters on your backup plans to reset the VSS usage before the backup starts.
- Edit the backup plan
- Advanced options
- Pre-post commands
Execute a command before the backup: YES
Command or batch file path on the machine with an agent: vssadmin
Arguments: resize shadowstorage /on=C: /for=C: /maxsize=[VALUE%]
For example: