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HP Raid Array - Partition Not Mounting

Posted on 2009-07-08
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Hi All,

We have an HP server with an HP MSA storage array attached to it.  The MSA had 2 raid arrays installed on it.  The 2nd array was not formatted or mounted when the server booted.  Using the HP raid utilities we removed the second array, and added the left over drives to the first array.  Then we expanded the size of the array to include the new drives.  At this point the partition on the first array was still available and mounted within the OS.  (The OS, is Cent OS Linux).  Once we rebooted the server we now get an error while trying to mount the partition :

mount special device /dev/cciss/c0d0p1 does not exist.

And the partition is no longer mounted and we cannot get access to all the data contained on it.

If we use fdisk or sfdisk we can see the partition still contained within the partition table.  But it wont mount, and we figure out why.  The critical issue is the data contained on that partition.  We must be able to get that information back.  Unfortunately our backup of the data doesn't contain all the newest information which is what we need to get back.  We need all the data back but the information not contained in the backup is key.

Also if we look in the /dev/ folder we see /dev/cciss/c0d0, which is the entire volume, but not the parition which contains the data.

Any assistance we can get it really helpful.
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Question by:erictreefrog
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3 Comments
 
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Expert Comment

by:Kerem ERSOY
ID: 24810058
Hi,

It seems that you've destroyed your /boot partition. I guess you'vedeleted your boot partition. You might need to boot your system in rescue mode and try to recreate your boot partition and then remount your root and try to reinstall a new kernel.

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by:andyalder
ID: 24830200
I'm not sure what filesystem you're using but some OSs get rather upset if you expand the disk from sub 2TB to over 2TB.
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erictreefrog earned 0 total points
ID: 24849532
We've figured it out. But first, some clarification:

- The system wasn't located on the array, just a large number of files.
- fdisk reported that the disk (/dev/cciss/c0d0) was partitioned with GPT, and to use parted to work with the disk.
- parted reported a malformed partition table and listed no partitions.
- Using the HP utility, we added the new drives to the first array, but didn't change the size of the partition.

So, our best guess is that the HP utility naively assumed that the disk was already partitioned with GPT, since the volume size was over 2TB, when in fact it used an MBR partition table, whose maximum partition (not volume!) size is 2TB.

We solved the problem by downloading and running the free TestDisk utility, and having it search the volume for lost MBR partitions (which it lists as "Intel/PC"), and recreate the partition table. It also has the ability to browse through and copy files from lost partitions, which is extremely handy. We were able to successfully rebuild the table, restore the volume, and retrieve the files.

For the future, though, we're backing up and reformatting the entire array with GPT in hopes of preventing this from happening again.
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