Cannot mount system partition

[maloo83]

I think I have killed my system partition (which sadly also contains my personal data): When starting my computer all I see is "error: unknown filesystem" and a grub rescue promt. Here is what I did: I booted a Ubuntu-Live-System via USB while my regular Ubuntu 11.10 system was in hibernate.

Now when I run fdisk -l from within the live system, this is what I see:


Device Boot Start End Blocks Id System
/dev/sda1 63 401624 200781 de Dell Utility
/dev/sda2 * 401625 56612976 28105676 7 HPFS/NTFS/exFAT
/dev/sda3 56614910 488396799 215890945 5 Extended
/dev/sda5 56614912 470808575 207096832 83 Linux
/dev/sda6 470810624 488396799 8793088 82 Linux swap / Solaris
Now when I try to mount sda5 or sda3 using "sudo mount -r -t ext4 /dev/sdaX /mnt", I get: wrong fs type, bad option, bad superblock, missing codepage or helper program, or other error" and dmesg contains the following:


[ 5925.202725] EXT4-fs (sda5): VFS: Can't find ext4 filesystem
[ 6025.811834] attempt to access beyond end of device
[ 6025.811843] sda3: rw=0, want=4, limit=2
[ 6025.811852] EXT4-fs (sda3): unable to read superblock
I'm totally desperate, is there anything I can try to recover my data?

Thanks in advance,
M

[darkod]

You can try TestDisk (you can download and run it in the live mode).
But first read carefully the manual on their page, and if you have any doubts ASK FIRST BEFORE DOING ANYTHING! :)
It can save your partition, but just as easy it can destroy it. Personally I never needed to use it, but people report excellent results.

sda3 can not be mounted, that is just the extended partition. But getting an error when trying to mount sda5 is not good.

PS. Forgot the testdisk link: http://www.cgsecurity.org/wiki/TestDisk

[maloo83]

Thanks a lot for the pointer to TestDisk. I installed it an ran it in analyze mode, this is what it returned:


TestDisk 6.11, Data Recovery Utility, April 2009
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org

Disk /dev/sda - 250 GB / 232 GiB - CHS 30402 255 63

The harddisk (250 GB / 232 GiB) seems too small! (< 346 GB / 322 GiB)
Check the harddisk size: HD jumpers settings, BIOS detection...

The following partitions can't be recovered:
Partition Start End Size in sectors
Linux 16335 44 30 42117 137 4 414193664
Linux 16338 157 12 42120 249 49 414193664
Linux 16340 167 20 42123 4 57 414193664


[ Continue ]
EXT4 Large file Sparse superblock Recover, 212 GB / 197 GiB
and the next page was


TestDisk 6.11, Data Recovery Utility, April 2009
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org

Disk /dev/sda - 250 GB / 232 GiB - CHS 30402 255 63
Partition Start End Size in sectors
* FAT16 >32M 0 1 1 24 254 63 401562 [DellUtility]
P HPFS - NTFS 25 0 1 3523 254 63 56211435 [OS]
L Linux 11514 1 1 12507 254 63 15968547 <-- selected row
L Linux Swap 29306 154 33 30401 254 63 17597506



Structure: Ok. Use Up/Down Arrow keys to select partition.
Use Left/Right Arrow keys to CHANGE partition characteristics:
*=Primary bootable P=Primary L=Logical E=Extended D=Deleted
Keys A: add partition, L: load backup, T: change type, P: list files,
Enter: to continue
EXT4 Large file Sparse superblock Recover, 8175 MB / 7797 MiB


Edit: Here are the results of a "deep analysis" run:


TestDisk 6.11, Data Recovery Utility, April 2009
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org

Disk /dev/sda - 250 GB / 232 GiB - CHS 30402 255 63
Partition Start End Size in sectors
* FAT16 >32M 0 1 1 24 254 63 401562 [DellUtility]
D HPFS - NTFS 25 0 1 3523 254 63 56211435 [OS]
D HPFS - NTFS 25 0 1 30400 254 63 487990440 [OS]
D HFS 1960 133 9 1981 254 63 345043 [ B]
D HFS 1964 238 46 1983 254 63 306261 [ F]
D HFS 1982 1 1 2002 254 63 337302 [ ^F]
D Linux 11514 1 1 12507 254 63 15968547
D Linux Swap 29306 154 33 30401 254 63 17597506



I did not create any HFS partitions, so something must be really messed up. But is there anything I can try to recover files from the system partition? E.g. take the options write or fix mbr?

Thanks a lot,
M


Thanks,
Maloo