Drive unreadable after breaking cluster

Posted on 2008-10-21
Last Modified: 2013-11-14
I have an old HP storage array (MSA1000) that was once connected to a WIndows 2000 cluster.  The array contains three LUNs.  The cluster has been broken (power supplies went out in the second node), and now only one of the three LUNs is readable by Windows.  The other drives are reporting "unreadable" in computer management.  The array controller is reporting that all LUNs, drives, controllers, etc. are working normally.  The other drives have data that we would like to retrieve.  Any thoughts on how to do this?  I've read other posts that suggest disabling the Cluster Disk Driver, but would like more information before pulling the trigger (does it make sense that that driver is "owning" two LUNs, but not the third?).  Thanks in advance!
Question by:christopher_perry
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LVL 22

Expert Comment

ID: 22775857
When the cluster died did it failover, was the dead node the owner of the non-accessible LUN's?

Author Comment

ID: 22775924
Not sure... it occurred the weekend before I started at the company.  Let's assume that is was the owner of those two LUNs, and the working node was the owner of the other (the current working LUN), does it make sense to disable the Cluster Disk Driver in the hopes that it releases the other LUNs from the "cluster?"
LVL 22

Accepted Solution

65td earned 250 total points
ID: 22777585
Can node 2 be brought back into the cluster?

No sure if stopping the cluster disk driver will do what you want.

Assisted Solution

VXDguy earned 250 total points
ID: 22837216
"that was once connected to a Windows 2000 cluster"

Does that mean that you're viewing the disks on a non-clustered server?

If so, you won't be able to break the SCSI reserve on the LUN.  Until you do, you're not allowed to read the disk.  Normal non-clustered disk driver does not issue SCSI reserve command nor do they break existing SCSI reserves.  A *clustered* server installs a disk driver that *does* issue SCSI commands and *will* break SCSI reserves--breaking reserves and re-issuing them from the surviving node is how clustering works to protect data integrity.

You may be able to remove the SCSI reserve by talking to HP support.  There may be a way to forcibly remove the reserve from the HP management tool.  HP support can also get a trace/dump of the array's current state and verify that it is indeed a SCSI reserve preventing SCSI read/writes from working.  SCSI inquiry is working otherwise the LUN won't show up at all and that's typical of a SCSI reserve problem (i.e. you can see it, identify see, view properties of it, but can't format or read from it).

Author Comment

ID: 22944041
Hey guys, sorry for my lack of activity here.  Management decided that they really didn't need the data after all, and had a tech reformat the drives.  Your ideas are good points of consideration, so I'm awarding the points equally.  Thanks again.

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