VSS writer error

Mike Davis

Backups are failing on a Hyper-V host. I ran:
vssadmin list writers and they are all stable, except this one:

Writer name: 'Microsoft Hyper-V VSS Writer'
Writer Id: {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}
Writer Instance Id: {51bed8ad-30e7-4657-abb3-8161879e3d1d}
State: [7] Failed
Last error: Timed out

I shutdown all the VMs, rebooted the host, brought the VMs up and that didn't fix it.

I ran this to re-register the VSS DLLs:

Re-registering Vss Dlls

cd /d %windir%\system32
net stop vss
net stop swprv
regsvr32 /s ole32.dll
regsvr32 /s oleaut32.dll
regsvr32 /s vss_ps.dll
vssvc /register
regsvr32 /s /i swprv.dll
regsvr32 /s /i eventcls.dll
regsvr32 /s es.dll
regsvr32 /s stdprov.dll
regsvr32 /s vssui.dll
regsvr32 /s msxml.dll
regsvr32 /s msxml3.dll
regsvr32 /s msxml4.dll
vssvc /register
net start swprv
net start vss

I still have the same result. What should I try next?

thwr

@Mike-Davis said in VSS writer error:

Backups are failing on a Hyper-V host. I ran:
vssadmin list writers and they are all stable, except this one:

Writer name: 'Microsoft Hyper-V VSS Writer'
Writer Id: {66841cd4-6ded-4f4b-8f17-fd23f8ddc3de}
Writer Instance Id: {51bed8ad-30e7-4657-abb3-8161879e3d1d}
State: [7] Failed
Last error: Timed out

I shutdown all the VMs, rebooted the host, brought the VMs up and that didn't fix it.

I ran this to re-register the VSS DLLs:

Re-registering Vss Dlls

cd /d %windir%\system32
net stop vss
net stop swprv
regsvr32 /s ole32.dll
regsvr32 /s oleaut32.dll
regsvr32 /s vss_ps.dll
vssvc /register
regsvr32 /s /i swprv.dll
regsvr32 /s /i eventcls.dll
regsvr32 /s es.dll
regsvr32 /s stdprov.dll
regsvr32 /s vssui.dll
regsvr32 /s msxml.dll
regsvr32 /s msxml3.dll
regsvr32 /s msxml4.dll
vssvc /register
net start swprv
net start vss

I still have the same result. What should I try next?

Event log?

I would probably check if there are any hardware failures and just reinstall the host. VSS errors shouldn't be taken lightly.

Mike Davis

This event gets thrown when I try to run a backup:

The description for Event ID 23 from source volsnap cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

If the event originated on another computer, the display information had to be saved with the event.

The following information was included with the event:

\HarddiskVolumeShadowCopy8
E:
\?\Volume{e9184b64-e4cd-49fa-9b8b-964df0eccbb5}

Mike Davis

A lot of articles say that the disk is out of space. This is what I have on that volume:
E:>dir
Volume in drive E has no label.
Volume Serial Number is 525D-42DA

Directory of E:\

05/07/2014 12:04 PM <DIR> Apps Backup
09/14/2016 12:25 AM <DIR> Hyper-V
09/30/2016 12:08 AM <DIR> temp
0 File(s) 0 bytes
3 Dir(s) 2,099,514,732,544 bytes free

Mike Davis

I also checked most of the VMs (there were a couple linux ones I couldn't) and they all have plenty of free space.

For anyone else that has a bunch of Windows VMs to check for free space, you can use the command:

Get-WmiObject -Class Win32_logicaldisk -ComputerName YourVMname

to check each one without having to log in to each individual VM.

Mike Davis

I also ran this command to make sure that space was allocated:

vssadmin add shadowstorage /for=e: /on=e: /maxsize=100GB

Mike Davis

vssadmin add shadowstorage /for=e: /on=e: /maxsize=100GB

did the trick. I had to use command line since this a Hyper-V core install.