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jmg999 · #1 (**permalink**) 06-06-2009, 10:20 AM

Hi,
First time poster, long time reader of the forums...
So, I'm running Ubuntu 8.04.1 LTS for servers. I run the OS on its own 250GB HDD. I also have an EXT3 3.2TB RAID-5 array. This is what's become unreachable. I've been having an issue w/ the onboard NIC, I believe. It causes kernel panics every so often, and the system has to be given a hard shutdown. Yesterday, when I attempted to restart it, I ran into some major difficulties.
First off, there was an indicator upon boot that there was some damage to the array. The suggestion was to run fsck. This took me into a management shell. Running an fsck didn't help, and I was given this message:

Code:

jeffe@USC:~$ sudo fsck /dev/sda1
[sudo] password for jeffe:
fsck 1.40.8 (13-Mar-2008)
e2fsck 1.40.8 (13-Mar-2008)
fsck.ext2: Superblock invalid, trying backup blocks...
fsck.ext2: Bad magic number in super-block while trying to open /dev/sda1
 The superblock could not be read or does not describe a correct ext2
filesystem.  If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>

So, trying this method for all my alternate superblocks, I was presented w/ this:

Code:

jeffe@USC:~$ sudo fsck -b 32768 /dev/sda1
fsck 1.40.8 (13-Mar-2008)
e2fsck 1.40.8 (13-Mar-2008)
fsck.ext2: Device or resource busy while trying to open /dev/sda1
Filesystem mounted or opened exclusively by another program?

However, the partition is not mounted, nor are there any processes running that are tied to it. Even running fuser couldn't resolve this. I then took a look at fdisk -l. It showed the partition had this filesystem type: EFI GPT. This is not correct. After reading everything I could find online, I finally made the decision to use fdisk to change the label back to 83 Linux. I did this, but it didn't help anything. When I try to run fsck or e2fsck, it still gets me nowhere:

Code:

jeffe@USC:~$ sudo e2fsck /dev/sda1
e2fsck 1.40.8 (13-Mar-2008)
e2fsck: Superblock invalid, trying backup blocks...
e2fsck: Bad magic number in super-block while trying to open /dev/sda1
 The superblock could not be read or does not describe a correct ext2
filesystem.  If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>
 jeffe@USC:~$ sudo e2fsck -b 98304 /dev/sda1
e2fsck 1.40.8 (13-Mar-2008)
e2fsck: Device or resource busy while trying to open /dev/sda1
Filesystem mounted or opened exclusively by another program?
 jeffe@USC:~$ dmesg |tail
[  386.826582] VFS: Can't find ext3 filesystem on dev sda1

I've tried from both single-user mode and logged in as myself. I've also booted to a live CD, hoping that the device would not appear to be in use; no luck. I even tried booting to a GParted live CD, but it was unable to see the partition that the array is on. If anyone has any new ideas, I'm open to trying it. This array has a great deal of data on it that is irreplaceable. Any help would be immensely appreciated. Thank you very much.

Jeff

nixcraft · #2 (**permalink**) 06-06-2009, 07:01 PM

Boot from Live CD.

Do not mount /dev/sda1. Running fsck on /dev/sda1 will result into data loss. Umount it:

Code:

umount /dev/sda1
fsck optionons /dev/sda1

jmg999 · #3 (**permalink**) 06-06-2009, 08:30 PM

Thanks for the reply. The partition is not mounted. You can see from the code I've posted that fsck isn't an option due to busy device issues, which must first be corrected.

nixcraft · #4 (**permalink**) 07-06-2009, 12:35 AM

EFI GPT is correct as fdisk command cannot create a partition size larger than 2TB. You have to use Intel EFI/GPT partition tables. Run following to get location of all superblocks and try them one by one (you may also need to change back to eft)

Code:

dumpe2fs /dev/sda1 | grep Backup

Also, if care is not taken data loss may occure so be careful.

nixcraft · #5 (**permalink**) 07-06-2009, 12:50 AM

Oh just incase if something goes wrong, use TestDisk to recover data TestDisk - CGSecurity

Good luck!

tiemen3r · #6 (**permalink**) 28-06-2009, 02:43 PM

Hi, Sorry for possibly digging up an old, irrelevant thread, but there might be more people looking for the solution. This is actually a bug in e2fsck, introduced in 1.40.7. Here's a link to a thread on the Ubuntu Forums with a reply (and a workaround!) from the maintainer himself: [ubuntu] e2fsck reports device as busy with -b parameter - Ubuntu Forums

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