Shadow Copy with a MS-Windows policy disk space

[Arturo_Lopez]

Hi everyone,

Yesterday we had a problem with a windows virtual machine. The technical support about this machine called to our group to say that they had a problem with disk space by VSS (Volume shadow copy service).
Yesterday I checked the backup (MS-Windows) and i didn't saw anything. The backup did it works and I didn't saw anythin strange. (I Only see a error 13 in the job overview but the completo job did it work).

I need to know how works the shadow copy with a ms-windows policy and if it's possible that this error did that the shadow copy didn't stopped and wrote more and more.

[Lowell_Palecek]

Check the bpfis and bpbkar logs on the client. Depending on the policy and configuration, the backup process (bpbkar) may trigger a snapshot process (bpfis). The bpfis log shows a snapshot taken and released. With VSS snapshots, you typically see two bpfis processes, the first to create the snapshot and the second to release the snapshot at the end of the backup. You can get a sense of the work flow by finding all the occurrences of "vss__" with a double underline character.

With the default Microsoft system provider, a VSS snapshot is copy-on-write. It starts tiny and grows every time a block is written to the volume that was snapped. The snapshot uses space in a configured location, and grows to a configured limit. Use vssadmin or similar tool to check the configuration.

[manatee]

fwiw, i always have VSS errors. before.

until i assigned a dedicated drive for VSS to use as a sort of scratchpad. why not try it.

hth.

[Arturo_Lopez]

Hi,

Today I proved the same situation of the error. I configured a windows virtual machine with a client 7.7.2. Launch the backup and check the ShadowCopy service and check with VSS comands:

vssadmin list shadows
vssadmin list shadowStorage

In the two commands appears the snapshot.

So, in the middle of this backup I rebooted the machine. In the activity monitor appeared the error 13 (File read Failed) and reconecting...
When the machine it's on, I have checked again the Shadows and the same proccess was running.
When netbackup recovered the conection and backup finished ok in the VSS was stayed the process running.
Netbackup not finished this process of the shadow copy and this is the problem that they have in the other machine.

The only method to stop this process that consum all space of the machine they did with the command DISKSHADOW -> DELETE SHADOWS ALL in the cmd.

Why happend this? What it's the process that do in the background netbackup?

Regards.

[Lowell_Palecek]

In both the systems that had the problem, was the computer rebooted during the backup? Doing so would interrupt the bpfis processes that were keeping track of the snapshot. The "same processes" you observed running after the reboot were new processes. The new bpfis processes would not know about the previous snapshot.

Diskshadow is the only way I know to delete the snapshots outside of NetBackup.

[Arturo_Lopez]

Hi,

Do you know if exitst some document to explain the process of MS-Windows backup step to step?

I triying to unsderstand what is the step to cause this problem?

Thanks