Backup fail with VSSwriter error

Question

Hello,
we currently are using Symantec Backup on tape and Windows Server Backup to make two differents backups on a SBS 2008.
We are getting failed backup randomly during the week for both. Sometimes one is succeed and not the others.
We have found several post about the VSS issues and how to fix it but nothing has changed.
What we have done:
- check the VSS writer and all is in "no error" state
- check the settings of the backups
- restart the VSS services
- Configure the Shadow Copy on the drives
- reboot the server
- Tried several solutions from forums
What we can see in the event viewer
ID 12289
"Volume Shadow Copy Service error: Unexpected error VSS_E_WRITER_STATUS_NOT_AVAILABLE. An older active writer session state is being overwritten by a newer session. The most common cause is that the number of parallel backups has exceeded the maximum
supported limit.  hr = 0x80042409. 
Operation:
   Aborting Writer
ID 7001
VssAdmin: Unable to create a shadow copy: The shadow copy provider had an error. Please see the system and application event logs for more information. 
Command-line: 'C:\Windows\system32\vssadmin.exe Create Shadow /AutoRetry=15 /For=C:\'. "
ID 12341
Volume Shadow Copy Warning: VSS spent 75 seconds trying to flush and hold the volume \\?\Volume{c22d5d46-0540-11e0-9496-806e6f6e6963}\.  This might cause problems when other volumes in the shadow-copy set timeout waiting for the release-writes phase,
and it can cause  the shadow-copy creation to fail.  Trying again when disk activity is lower may solve this problem. 
Operation:
   Executing Asynchronous Operation
Context:
   Current State: flush-and-hold writes
   Volume Name: \\?\Volume{c22d5d46-0540-11e0-9496-806e6f6e6963}\"
Some will post the link of "how to troubleshoot VSSwriter issue": we have already used it.
Does someone have a fresh idea about this issue ?
Thanks in advance

Answer 1

Hi Nerea,
Before going further, would you please let me confirm if temporarily disable either of the two backup, will
another backup operation run smoothly? In other words, if temporarily disable Symantec Backup, will Windows Server Backup always run successfully? Or if disable Windows Server Backup, will Symantec Backup always run successfully? Please check if Windows Server
Backup conflicts with Symantec Backup.
Based on the error message, please run
chkdsk command and check if there is any issue in the disk. Then use
Vssadmin resize shadowstorage to resizes the maximum amount of storage space that can be used for shadow copy storage. And check if this issue still persists.
In addition, would you please let me know whether re-register Volume VSS components? If this issue still persists,
please re-register and monitor the result.
From command prompt:
cd windows\system32
Net stop vss
Net stop swprv
regsvr32 ole32.dll
regsvr32 vss_ps.dll
Vssvc /Register
regsvr32 /i swprv.dll
regsvr32 /i eventcls.dll
regsvr32 es.dll
regsvr32 stdprov.dll
regsvr32 vssui.dll
regsvr32 msxml.dll
regsvr32 msxml3.dll
regsvr32 msxml4.dll
net start swprv
net start vss
By the way, did the Symantec Backup and Windows Server Backup run at the same time? Or before one backup finished,
had another backup started?
Hope this helps.
Best regards,
Justin Gu