DPM 2012 – Drives Invalid

Had an odd one with a customer today, where some volumes within the DPM server had gone into an “INVALID” state and you couldn’t reactivate the disk.  Rebooted and yet more drives went offline, gone from 80 volumes to 57 working.  So lets give you a run down of the environment:

DPM 2012 R2 running as a Virtual Machine with 80x 1TB Volumes on a Scale out File Server (SOFS) with De-Dupe (works a dream by the way 84% dedupe rate).

So after some desperate googling came across something similar which mainly related to SAN volumes.  Thanks to Peter Zerger over at System Center Central for this one.

SAN policy was been introduced in Windows Server 2008 to protect shared disks accessed by multiple servers. The first time the server sees the disk, it will be offline, but after being brought online once, should be online even after reboot.You can change the San Policy setting to OnlineAllsetting to get around this, but it must be very clear that if the disks are shared among servers, this can lead to data corruption. Users are encouraged to use the proper SAN policy to protect data.

However, the VHD file in a highly available VM is not a shared disk in the same fashion, so in this case it should be safe. To avoid the issue newly deployed virtual machines, you’ll need to implement the fix in the VM before you sysprep the OS (create a template). You can check the current setting of the San policy using the DISKPART utility as follows:

DISKPART.EXE

DISKPART> san

SAN Policy : Offline Shared

The Fix

The fix is to use the DISKPART utility is to make a SAN policy change within the VM that is running DPM. The steps are once in DISKPART:

DISKPART> san policy=OnlineAll

DiskPart successfully changed the SAN policy for the current operating system.”

After this you should be able to bring your drives back on after a reboot.