Hi there,

I am unable to boot Ubuntu on DISK A (partition SDA1) since I added another SATA disk (DISK B) (from another computer which had graphics card hardware failure). DISK B runs Ubuntu as well, and I was able to boot from that disk. However, after removing DISK B, I am unable to boot DISK A again.

Booting from DISK A says now something on GRUB and no operating system found.

Trying to fix it, I installed Ubuntu successfully on another partition (SDA3) of DISK A and tried to mount partition SDA1 (when running the freshly installed Ubuntu from SDA3).

When trying to mount I get following error:
"mount: you must specify the filesystem type"
The partition SDA1 is still there but seems to have lost some header information such as filesystem type (which is EXT4).

When specifying the filetype I find in the syslog:
EXT4-fs (sda1): VFS: Can't find ext4 filesystem


Any idea? How can I repair the header of partition SDA1?

Thanks!
Bart

SYSTEM INFORMATION:
---------------------------------
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ca4fe

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 976764927 488381440 83 Linux
/dev/sda2 1467109374 1953523711 243207169 5 Extended
/dev/sda3 976768065 1467108637 245170286+ 83 Linux
/dev/sda5 1943758848 1953523711 4882432 82 Linux swap / Solaris
/dev/sda6 1467109376 1927149567 230020096 83 Linux
/dev/sda7 1927151616 1943752703 8300544 82 Linux swap / Solaris


bart2@bart2-H67MA-UD2H-B3:~$ sudo parted -l
Model: ATA WDC WD10EALX-009 (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 500GB 500GB primary boot
3 500GB 751GB 251GB primary ext4
2 751GB 1000GB 249GB extended
6 751GB 987GB 236GB logical ext4
7 987GB 995GB 8500MB logical linux-swap(v1)
5 995GB 1000GB 5000MB logical

Normally you get that error message when there is no filesystem on the partition. The disks might not be showing up in the order expected.

Since you tried to install something, again, you may have made the original system on disk A unbootable or unrunnable.

Boot a LiveCD. Mount the partition you have running as the "/" mount point, but this time at "/mnt", like maybe (you choose the correct device):

If that works, try this:

and see if that works.

If it had a valid (known) filesystem, parted should have found it.How did you come to that conclusion ?.
It's entirely possible the whole partition has been trashed. You might need to use something like photorec or foremost to see if (some of) your files still exist.

BTW, when posting listings, use [code] tags as per above.