dennytay
1 Copper

PERC 6/e - Retag VD with original cleared foreign config drive

I have a Dell R710 server with a PowerVault 1000 RAID array that is down. THe server has a two SAS drive mirror RAID so the OS (WIndows Server 2008) is bootable and accessible. The array is a 15 drive RAID 5 with no hot spares (all drives used in RAID set).

I had drive 14 go bad two days ago and replaced it with a new HD and the controller started doing the rebuild of the drive. I let that run overnight expecting to have the drive rebuilt and the RAID back in good order the next morning. However things didn't go as well as I was expecting. The next morning I came in to find that drive 10 was flashing amber and had failed as well.

When I looked at the situation within the Openmanage Server Administrator it was unapparent whether or not drive 14 had completed its rebuild - but the fact that it was not online leads me to believe that it did not complete before drive 10 failed.

I pulled drive 10 and reseated it within the enclosure, powered down and rebooted. Upon coming back up drive 10 seemed to come back to life - both lights above the drive are now green and where it used to say "Failed" under the PD Mgmt it now said Ready. I also received the "Foreign Configuration" alert and from what I was able to surmise from another post on this forum, I chose to clear the foreign configuration for that drive and was under the assumption that the configuration within the controller was the one that I wanted to stick with. However, now the drive shows up under the Physical Disk section as "Ready" as opposed to "Failed" - but it is still showing up as missing within the Virtual Disk page. The same situation took place with drive 14 (the original failed disk that was rebuilding) - after removing the drive and re seating in the enclosure it came up with the foreign configuration and I cleared it as well.

So at this point my hope is that drive 10 is working again - and it has enough life left in it to get the virtual disk back online so that I can (hopefully) access/move some important data on the drive and possibly restart the rebuilding of drive 14. 

I found a post on this forum that had similarities to my situation and the DEll representative mentions a process called "a retag" where You delete the VD configuration on the controller and then recreate the array with out initializing. He mentions that It won't affect the data, UNLESS we retag the array to a different configuration than it was prior. 

He mentions: Run a Dset report in the OS prior to doing anything and then let me see the report to get the correct raid configuration on the virtual disk. Then we can retag it accurately.

For your reference here is a link to that forum post: http://en.community.dell.com/support-forums/servers/f/906/t/19597921

Does this seem to be a viable option for my situation?

Thanks!

   

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lfeldman
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RE: PERC 6/e - Retag VD with original cleared foreign config drive

If a RAID5 array fails during the rebuild(this is actually very common because a rebuild puts heavy stress on all drives) that means that there is no way to safely continue the rebuild without risking data loss.

The reason drive 10 failed the first time is because itt couldn't survive the rebuild. attempting another rebuild with that drive WILL cause further corruption and possibly unrecoverable data loss.

Further because you have now cleared the configuration on drive 10 and drive 14, there's no way to restart the rebuild properly even if you wanted to.

You can't retag the VD because you have 2 different(inconsistent) parity sets on the array now and 2 drives with no configuration data.

Your best bet is to restore from backup to a fresh array(test individual drives for stability before reusing them)

if you don't have an up to date valid backup then you need professional data recovery help.

Here's a list of dell preferred partners for data recovery:

www.dell.com/.../EN Partners

and further info about RAID recovery:

www.raiddatarecovery.com

www.drivesaversdatarecovery.com/.../raid-data-recovery

Best of luck.

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