05-11-2010 01:49 PM
We have some problems with the VSS Hardware provider on an MSA2012fc, in particular with the snap pool management. We are using at the moment microsoft data protection manager 2010 to back up virtual machines in an hyper-v environment that resides on a cluster shared volume on the MSA2000. the problem is that this backup software tries to create a temporary snap pool on the available storage of the MSA to make the backup, but it says that the available storage is not sufficent. on the VSS Provider log file we have the following error:
: calculateReserveSize(): getBackingStoreSize(Volume_Name): 569765M
: LogErrorEvent: Current Locale is: English_United States.437
: Logging Error Event "calculateReserveSize(): The vdisk doesn't have sufficient space to create snap pool:array id=00C0FFD739610000A368AD4900000000".
now the question is: how this "calculateReserveSize()" function works?
can we modify it?
cause manually creating the snap pool and assigning it to the master volume the backup works (unfortunately the backup software wants to create the snap pool by itself and after it finishes the backup it deletes the "manually created" snap pool... so we have to recreate each time, for each backup, the snap pool...)
thanks in advance to all and please ask if there is someting that I must better explain
08-03-2010 11:18 AM
any update on this? we are having the same issue.
calculateReserveSize(): The vdisk doesn't have sufficient space to create snap pool:array id=00C0FFD887DB00008E74804A00000000
08-18-2010 02:00 PM - edited 08-18-2010 02:02 PM
I have the same problem with MSA2324sa G2, Cluster Hyper-V Windows Server2008R2 and DPM2010.
After several tests the only solution that works is to leave a space of at least 20% of the volume on the same Vdisk as explained in the Reference Guide (trying to create a snapshot through the web interface of msa2324sa without errors).
So, snap-pool and master volume are created and deleted automatically each time by the VSS provider.
I hope this will be helpful for you.
08-23-2010 07:44 AM
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.
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