Ext3 partition not mounting anymore

Krappe · 04-09-2007, 03:32 PM

Hello,

First of all, if this thread doesn't belong in the Hardware forum, I apologize.

Anyway, I have an ext3 partition that doesn't mount anymore. First I had a problem with a bad magic number in superblock, or something along those lines. I ran e2fsck with an alternative superblock. e2fsck found lots of errors, and corrected them all.

But alas, the partition still doesn't mount.

Code:

$ sudo mount /dev/sdb1 -t ext3 -o ro,sb=393216 recov/
mount: wrong fs type, bad option, bad superblock on /dev/sdb1,
       missing codepage or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

$ dmesg |tail
[ 1528.848770] EXT3-fs warning: feature flags set on rev 0 fs, running e2fsck is recommended
[ 1528.854792] EXT3-fs: fragsize 1024 != blocksize 4096 (unsupported)

A weird thing though -- the fragment size is 4096, according to this:

Code:

$ sudo mkfs.ext3 -n /dev/sdb1
mke2fs 1.40-WIP (14-Nov-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
758016 inodes, 1514118 blocks
75705 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=1551892480
47 block groups
32768 blocks per group, 32768 fragments per group
16128 inodes per group
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736

I haven't found anything helpful on Google, and I'm starting to freak out. Important data was stored on this partition -- now I guess I'm going to back up sensitive stuff each day! I'd really appreciate any help.

x_terminat_or_3 · 04-09-2007, 03:46 PM

Any chance these problems started after trying to dual boot winblows?

Krappe · 04-09-2007, 03:54 PM

Well uh, I don't know what exactly made it fail.

I pulled this hard drive from a working computer. Linux was installed on this hard drive, and it worked perfectly. I wanted to copy the data from this hard drive to a Windows XP computer, indeed. So I put the hard drive as a slave drive in the second computer, and I installed the ext2 driver for Windows.

It ran fine twice (and I hadn't recovered the data yet during these two times), and then the hard drive was shut down improperly -- the molex connector has been pulled while the hard drive was still running. Since then, I guess something went corrupt, and Windows doesn't want to mount it either.

x_terminat_or_3 · 04-10-2007, 04:17 PM

I have had a similar bad experience but not when using winblows to mount my ext3, it was during startup, winblows overwrote the partition type of my ext3 partition to vfat. And to fix it all I had to do was tell grub to change the partition type back to ext3.

Don't know if this applies, but when you are at the grub screen, press c to get a shell, then do root (hd0, and then press tab. It will list all the partitions on that drive, including their parition types. Verify that those are correct, and repeat for the other disks.

Krappe · 04-10-2007, 06:20 PM

Actually, I've screwed around the partition a bit since it fails to mount. I don't have enough space to hold a dump that big, hence I didn't back up the partition.

Before I messed around the partition, though, GRUB was stuck just before displaying the menu.

Since then I tried various pieces of software to recover the data. Now, parted doesn't see the partition as a 'Linux' partition anymore.

I've tried to run e2retrieve, to no avail. It froze after a while, and didn't recover anything.

I've also tried the demo version of a Windows shareware, called Stellar Phoenix Linux 2.5, and it seems to see most of my 'lost' files. But it won't recover anything unless I shell out $80 for the full version.

I gave up on mounting the partition, I think it's too badly damaged. But if there's an ext2 data recovery tool in the Windows world, there must be something decent for Linux, right?

Thanks for any help.

EDIT: parted did see it as an ext3 partition before I tried any data recovery software, and the partition didn't want to mount. Amongst the ton of software I tried out today, there might've been a crappy piece of software that wrote to the partition table.

Krappe · 04-11-2007, 04:09 AM

I've just tried out the Sleuth Kit with the Autopsy browser, and I'm greeted by:

Code:

Cannot determine file system type
Invalid magic value (not an EXTxFS file system (magic))

So it apparently cannot recover the directory tree, or lost files. How can I turn the partition type back to ext2 or 3? Thanks a lot.

EDIT: Ok, I've just tried to feed Autopsy with a partial backup of the partition. (It only contains the four first gigabytes) And I got:

Function not supported (This file system has fragments that are a different size than blocks, which is not currently supported

Hmm. Looks familiar. I got the following error on April 9th when trying to mount it:
[ 1528.854792] EXT3-fs: fragsize 1024 != blocksize 4096 (unsupported)

Sigh. Anything I can do?

x_terminat_or_3 · 04-25-2007, 05:10 PM

Don't know if this applies, but when you are at the grub screen, press c to get a shell, then do root (hd0, and then press tab. It will list all the partitions on that drive, including their parition types. Verify that those are correct, and repeat for the other disks.

If not correct do a parttype your_partition type

Where type is hex code for magic number which should be 0x83 for ext2 and ext3

Krappe · 04-29-2007, 07:47 AM

I decided to give up some time ago.

I had to admit that the hard drive has just been screwed up badly, and nothing could be done about it. I've tried everything I could think of.

Moral: I've learnt the hard way I'd have to backup my data more seriously.

Thanks for your time anyway, x_terminat_or_3.