We have a Hyper-V 3.0 Failover Cluster (2 servers) each running Windows Server 2012 RC. We have Shared Storage (HP P4300) which is reporting no errors and is working just fine as either a standalone disk or witness disk within the cluster. We have also installed the HP P4000 DSM which is also working fine (this is on one of the Hyper-V nodes and has full access to the disk).

The issue is that when we add the Cluster Disk (which initially reports as Online with 'Available Storage' status) as a Cluster Shared Volume, it briefly reports as Online until reverting to Online (No Access). They do not appear in C:\ClusterStorage as they should on either of the member nodes. There are no errors or warnings in the log and the only informational message is that the disk was brought online.

To further confuse things, enabling 'Maintenance Mode' on the disk changes the status to Online (Maintenance Mode) and the disk now appears in C:\ClusterStorage (on the node where the cluster disk is located) and allows read/write access just fine.

There doesn't appear to be any information regarding Online (No Access) on the internet, so any information at all would be very much appreciated right now.

Results of a 'Validate Cluster' only brought back the following relevant errors:

Successfully issued call to Persistent Reservation REGISTER using Invalid RESERVATION KEY 0xc, SERVICE ACTION RESERVATION KEY 0xd, for Test Disk 0 from node PRODHV1.prodhv.local.

Test Disk 0 does not support SCSI-3 Persistent Reservations commands needed to support clustered Storage Pools. Some storage devices require specific firmware versions or settings to function properly with failover clusters. Please contact your storage administrator or storage vendor to check the configuration of the storage to allow it to function properly with failover clusters.

These errors do seem most relevant to the issue and would probably cause it, although the P4300 supports SCSI-3 as far as I can tell. (source)

EDIT: Just some more information to fuel the fire, this works perfectly well on Server 2008 R2, so I know that SCSI-3 is actually supported on the device. Whether the DSM Driver works well under 2012 or not is a different matter, but it may well be that.

  • Have you validated the cluster? That's almost certain to tell you where the problem is. Seems to me as if your storage isn't allowing multiple host access to a single LUN. Commented Aug 7, 2012 at 12:47
  • @ChrisMcKeown Thanks, just ran a validation and the only real error is that which I have updated the answer with now. Commented Aug 7, 2012 at 13:50
  • Your running beta software with unsupported drivers... expect problems (the kind you can't "solve" yourself). It looks like the DSM driver is not working correctly in Server 2012. You'll have to use the MS Driver (with the lesser functionality) or wait for HP to release a DSM that's compatible with Server 2012.
    – Chris S
    Commented Aug 7, 2012 at 14:47
  • @ChrisS Don't worry, definitely expecting problems. Just not unsolvable ones! :) Commented Aug 7, 2012 at 14:48
  • Update - The MS DSM didn't work, disabling MPIO didn't work. We're trying to contact HP Support to see when support may be available, but not expecting too much on that front. Commented Aug 7, 2012 at 15:52

2 Answers 2


The ability to have Persistent Reservations is important - it allows to cluster to ensure that the only nodes which have the ability to access and modify the LUN are the ones that belong to the cluster.

You may need to ensure that you have the latest firmware for your SAN, the latest drivers and DSM. It appears that you're not alone although that thread is quite old.

  • We've just updated the SAN's firmware and still having the same issue unfortunately. We're going to try using Microsoft's default DSM driver and see if that works, but then the SAN only runs in Failover mode. Commented Aug 7, 2012 at 14:21

Based on the error message and the information you posted the storage device is either not loaded with drivers that support concurrent access or your device does not support multi-host access to begin with.

Are you sure you have a 2012 approved driver and that your device supports multi-host access?

  • The HP P4000 DSM for MPIO driver is showing as running on boot and is signed, despite the status being "Degraded". I'm not sure what that means, but the default MS driver is also showing as "Degraded" as are a few others. EDIT: Also just to confirm that this did work on Server 2008 R2 also, we'd just like to utilise Hyper-V 3.0 features. Commented Aug 7, 2012 at 14:25
  • It's possible the latest drivers and firmware have simply not been updated yet to support the 2012 requirements. I'm not sure. Commented Aug 7, 2012 at 14:27
  • Definitely seems most likely yes, it's just a little weird to me that 2008 R2 signed drivers wouldn't work on 2012. As far as I can tell the requirements didn't change so much. Commented Aug 7, 2012 at 14:30
  • No but the functionality certainly did to support seamless cross-network moves of VMs. Commented Aug 7, 2012 at 14:47

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