Identify which disk recovery points are stored on?

Question

We have 3 disks in DPM, one of which is flaky and keeps going missing from DPM.  We started by migrating our most important datasources to another disk (on a temporary basis) while we ordered a new SAN with the view to moving everything onto the new
SAN.  This has worked for most datasources but I have a problem with one.
For the purpose of this thread we have:
Disk 1 - old, flacky disk
Disk 2 - temporary disk
Disk 3 - new SAN
I am trying to move a datasource from disk 2 to disk 3 but am getting the following error:
Set-ProtectionGroup : D:\ has recently been migrated. You cannot migrate D:\ again until the recovery points on the previous replica volume are available.
(ID: 31224)
At C:\Program Files\Microsoft System Center 2012\DPM\DPM\bin\MigrateDatasourceDataFromDPM.ps1:129 char:4
+             Set-ProtectionGroup $mpg
+             ~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Set-DPMProtectionGroup], DlsException
    + FullyQualifiedErrorId : ChainedMigrationError,Microsoft.Internal.EnterpriseStorage.Dls.UI.Cmdlet.ProtectionCmdLets.CommitProtectionGroup
Prior to attempting this, I removed (using remove-recoverypoint) the old recovery points I believed to be on Disk 1 rather than waiting for them to expire on their own.  This worked for other datasources but doesn't work for this.
I found an SQL query on another fourm post and ran it:
use DPMDB  
select dsk.NTDiskNumber,vol.MountPointPath,ag.NetbiosName, ds.DataSourceName,  vol.Usage as "1=REPLvol 2=RPvol", vol.VolumeSize,lr.lastbackuptime
from tbl_IM_DataSource as ds
join tbl_PRM_LogicalReplica as lr
on ds.DataSourceId=lr.DataSourceId
join tbl_AM_Server as ag
on ds.ServerId=ag.ServerId
join tbl_SPM_Volume as vol
on lr.PhysicalReplicaId=vol.VolumeSetID
and vol.Usage in (1,2)
join tbl_SPM_Extent as ext
on vol.guidname=ext.guidname
join tbl_SPM_Disk as dsk
on ext.diskid=dsk.diskid
where ntdisknumber=4 and lastbackuptime < getdate()-7 and NetbiosName='FILESERVER1'
order by lastbackuptime
and the output is:
NTDiskNumber MountPointPath
NetbiosName DataSourceName
1=REPLvol 2=RPvol VolumeSize
lastbackuptime
4 File System\vol_783bc0f9-8382-4df5-8f72-819ba012f68f
FILESERVER1 D:\
2 359766425600
2014-05-13 08:01:08.000
4 File System\vol_783bc0f9-8382-4df5-8f72-819ba012f68f
FILESERVER1 D:\
1 2238049157120
2014-05-13 08:01:08.000
Is that DPM telling me there are still recovery points on that disk?  If not, is there a way to tell which recovery points pertaining to this datasource are still on Disk 1?

Answer 1

That message sounds like it expects data to be on the old disk but it may be having issues.  These are all dynamic volumes so taking the disk offline and then back online usually fixes dynamic disk errors.  Then do a rescan in DPM.
I usually find the volume on the disk by using disk manager. 
Go to the protected item (e.g. VM, volume, etc.) in the Protection view
In the bottom pane, choose the Click to view details link to get the path
Right-click on the path and copy it.
Paste the path into Notepad or similar so you can see it
In the path, there will be a GUID prefixed by "vol_"
Open Disk Manager (diskmgmt.msc)
Look for the volume that has DPM-vol_GUID where GUID is from step 6.  Click on it and that will highlight the partition in the display at the bottom of disk manager.  That is the disk that holds all the data for that protection item.
Sometimes it can be hard to tell which partition is highlighted on the disk and I'm sure there is a simpler, more elegant way. 
After you find the partition, you could clone it onto a new disk.
You may have to end up just replacing the disk and recreating the replica.  You can do that by following the information in this post (http://social.technet.microsoft.com/Forums/en-US/fa0402d3-67d4-4fe5-8ed1-5666fd6b0ff6/dpm-disk-failure?forum=dpmstorage). 
Replace the bad drive and then run DPMSYNC -Reallocatereplica.
Not sure if this helps...
Rob