P2000 is deleting my Snap Pools - Cannot perform data backup more than once

[Drumgod007]

I do not have a resolution at this time. But i can help provide you with a work around.

This had to be performed before each backup, as the P2000 will 'undo' this action once the backup is complete.

Go into the Web utility and manually make a snap pool for the partiitions that you need to backup.

Telnet into the array controller and conver the target volume from standard to master via this command (this is case sensitive)

convert std-to-master snap-pool <snapPoolname> <vdisk_volume>  

Ex: If your target volume is D: then enter this syntax.

convert std-to-master snap-pool vDisk_D_sp001 vDisk_D_Vol1

Repeat this for all volumes that are giving your problems with your back.

You can verifiy this worked by typing show volumes into the CLI via telnet. I will do a 'show volumes' before and after the conversion to make sure it work properly.

Perform your backup now.....

Since i have two volumes that both delete my snap pools automatically i have to do this command twice. Once for my D: drive and again for my B: Drive. 

Please let me know if you find a more permante solution. My general assumption is that the snap pools are being deleted and re-purposed for other volumes by some policy. I just have not have the time to investigate further. I suspect that if i delete my older snapshots, and increase the free space on the other volumes, then the P2000 may stop automatically deleting my snap pools on my other volumes.

IT WOULD BE GREAT FOR HP TO CHIME IN ON THIS PROBLEM................. HINT HINT HINT.............

[JirkaV]

Thanks for your answer. I use same steps, but it is not possible for our customers :-). I looking for any script tool for automatization this before backup process.

Jirka

[Drumgod007]

I think the real solution would b for HP to figure this out, and provide us with a resolution.

Obviously this is an issue with the P2000 that needs to be addressed.

What have you to say HP????????????

[JirkaV]

My backup jobs finished ok now. Last job cleaned all pool. I didn't make any changes. The new job correctly create pool and snapshot and working ok. I didn't make any changes in configuration DPM and MSA.

[RandyHood]

There is a wonderful explaination from Jon Paul in this thread:

http://h30499.www3.hp.com/t5/Network-Attached-Storage-NAS/MSA2012fc-VSS-Provider-Snap-Pool-Problems/td-p/1151737

[Drumgod007 · Accepted solution]

The link above fixed our issues with the P2000 automatically deleting our snapshots. Referenece this information here, and the registry change..

By default, the VSS Provider will attempt to convert standard volumes to master volumes on demand, automatically allocating and deallocating snap pools as needed.  This mode of operation works best for turnkey configurations where the number of available snapshot licenses is less than the number of volumes and manual conversion of standard volumes to master volumes would be inconvenient.  However, there are two potential drawbacks to the default behavior:

Insufficient free space on the vdisk

Creating snapshots on a standard volume may fail with the following error posted to the Applications event log:

calculateReserveSize(): The vdisk doesn't have sufficient space to create snap pool

This error occurs when the standard volume's vdisk does not contain enough free space to allocate a backing store which is at least 20% of the size of the volume, or 6GB, whichever is larger.  To avoid this problem, find or create a snap pool on another vdisk with sufficient free space and convert the standard volume to a master volume using that snap pool instead.  Placing the snap pool on a separate vdisk may also improve performance if the other vdisk is not subject to a heavy I/O load.

Snap pools are automatically deleted

In order to help manage limited disk space and snapshot licenses, the VSS Hardware Provider will, by default, automatically convert master volumes to standard volumes when the last snapshot for the volume is removed, and automatically delete snap pools when no snapshots refer to them.

However, this mode of operation may cause problems in environments where some manual management of snap pools is desired, or in SAN environments where multiple hosts are using VSS to create and delete snapshots concurrently on the same array.

To avoid these issues, the VSS Hardware Provider can be configured so that it does not attempt to automatically create or delete snap pools or convert standard volumes to master volumes and vice versa.  Instead, the administrator must perform these steps manually.

Solution

To disable automatic conversion of standard volumes and automatic creation and deletion of snap pools, enter the following command at the Windows command prompt to change the provider's StandardVolumesAreSupported parameter value to 0:

reg add "HKLM\SYSTEM\CurrentControlSet\Services\HP StorageWorks VSS Hardware Provider\Parameters" /v StandardVolumesAreSupported /f /t REG_DWORD /d 0 

To restore the default behavior, change the value of StandardVolumesAreSupported back to 2:

reg add "HKLM\SYSTEM\CurrentControlSet\Services\HP StorageWorks VSS Hardware Provider\Parameters" /v StandardVolumesAreSupported /f /t REG_DWORD /d 2 

After changing the StandardVolumesAreSupported value, the VSS server must be stopped if it is currently running:

net stop VSS

net stop "HP StorageWorks VSS Hardware Provider"

Alternately, reboot the server to ensure that all the VSS components have been restarted.

As you stated that the Snap-pool can be created and the operation completes ok following that but then de-allocates the snap-pool, I believe that changing the VSS provider behavior and leaving the snap-pool should resolve the issue you are seeing