Shadow Copy Components backups may complete partially if VSS writers shows error "No component files present on the snapshot" during backup

Problem

Shadow Copy Component backups of a new Windows 2008 or later client completes with status 1.

Error Message

Cause

Using VSP on Windows 2008 can cause unexpected behavior with VSS writers. It is recommended to always use VSS for Windows Open File Backups on Windows 2003/2008 or later clients.

Solution

1. Verify no backup jobs are active for the client, run vssadmin list writers on the affected client: confirm all writers are listed as State: [1] Stable

2. If any writers are not in a stable state, reboot the client to reset the writers

3. Check the Windows Open File Backup setting on the master server to ensure VSS is being used
Host Properties > Master Servers > (master) > Client Attributes > Windows Open File Backups tab
Ensure the client name is added to this list, then highlight client in the list, and select 'Use Microsoft Volume Shadow Service (VSS)'

4. This error can also happen if the snapshot size exceeds the snapshot maximum size 'Use limit' configured for the volume.  If this happens, Windows will automatically delete the snapshot, even though NetBackup still wants to use it.

This message may be observed in the System Event Log at the time of the backup error:
* VolSnap I33 The oldest shadow copy of volume C: was deleted to keep disk space usage for shadow copies of volume C: below the user defined limit.

To check the Maximum size 'Use limit':

A. Open My Computer > right-click on the C:\ drive > select Properties
B. Select the 'Shadow Copies' tab
C. Select the C:\ drive and click 'Settings' to view the 'Use limit' values

* If 'No limit' is selected, then Windows will not delete the snapshot regardless of how much space it consumes.   However, if the snapshot is very large, and there is not much disk space left on C:\, then it might be failing to create the snapshot due to space restrictions.

** If 'Use limit' is specified, make sure the specified value is large enough to contain the snapshot with room to spare.  Veritas recommends no less then 1 GB.  Microsoft recommends the snapshot 'Use limit' be configured for roughly 10% of occupied space. For example, if the C:\ drive has 100GB of data on it, the 'Use limit' should be set to 10 GB.