This article applies to:
OS: All windows OS post WS 2003
Product edition: inSync Cloud/On-Premise/Phoenix
Overview
This article provides the basic steps to resolve VSS issues before you address error messages or resort to advanced troubleshooting.
Troubleshooting steps
Check Windows event logs:
Check both the application and system event logs for detailed VSS errors. Subsequently, also check the Hyper-V VMMS events.
Check third-party backup software:
Check for any third-party backup software. If found, uninstall it and reboot the server.Check Shadow Storage Space:
Check the storage on each server with the below command.
vssadmin list shadowstorage {/for=<ForVolumeSpec> | /on=<onVolumeSpec>}
Reference: vssadmin list shadowstorage
Example:
vssadmin list ShadowStorage /for=E:\
📝 Note
If there is less shadow storage space allocated, increase the storage in accordance with the requirement or set it to unlimited.
vssadmin resize shadowstorage /for=<ForVolumeSpec> /on=<OnVolumeSpec> /maxsize=<MaxSizeSpec>
Example:vssadmin resize shadowstorage /For=E: /On=E: /MaxSize=UNBOUNDED
Delete any stale and old shadow copies using the following command:
Vssadmin delete shadows /all
Check Writers StatusVSS backups fail if application-specific writer, such as hyper-v writer or SQL, fails.
Check the writer status with the following command:
Vssadmin list writers
The output must include all the writers listed and must be in a stable state.
Troubleshoot unstable/failed writers using the common steps:
Check the service account of the corresponding writer. Ensure it is a system account.
Check the event log.
Check the service of the corresponding writer. List of some corresponding services mentioned below:
Hyper-V Virtual Machine Management
SQL Server VSS Writer
Oracle VSS writer
System Writer
Restart the concerned service and run the above command again.
Advanced troubleshooting steps for unstable/failed writers.
Restart COM+ System Application Service
Restart Distributed Transaction Coordinator Service
Restart Volume Shadow Copy Service
Restart the corresponding VSS writer service. For example, Hyper-V VSS writer or SQL VSS writer
Re-register all VSS & COM+ components.
Run the following command using elevated command prompt.
cd /d %windir%\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 regsvr32 Vssapi.dll regsvr32 Vssui.dll regsvr32.exe /i %windir%\system32\eventcls.dll regsvr32.exe /i %windir%\system32\swprv.dll regsvr32.exe %windir%\system32\vssui.dll regsvr32.exe %windir%\SysWOW64\vss_ps.dll regsvr32.exe %windir%\SysWOW64\msxml.dll regsvr32.exe %windir%\SysWOW64\msxml2.dll regsvr32.exe %windir%\SysWOW64\msxml3.dll regsvr32.exe %windir%\SysWOW64\msxml4.dll regsvr32.exe %windir%\SysWOW64\ole32.dll regsvr32.exe %windir%\SysWOW64\oleaut32.dll regsvr32.exe %windir%\SysWOW64\es.dll regsvr32.exe %windir%\SysWOW64\comsvcs.dll vssvc /register net start swprv net start vss net stop winmgmt regsvr32 wmiutils.dll net start winmgmtMultiple Providers
At the elevated command prompt, run the following command
vssadmin list providers
The output must list one or maximum two providers as follows:
'Microsoft Software Shadow Copy provider 1.0
Microsoft File Share Shadow Copy Provider
If there is any provider other than the above two, disable and stop the services corresponding to these providers. For example, the following providers.
Acronis VSS HW Provider
StorageCraft Volume Snapshot Software Provider
To resolve any VSS-specific errors, use the solutions provided in the Troubleshooting VSS errors section.
For advanced troubleshooting such as VSS trace, refer the Microsoft blog Using Tracing Tools with VSS.