Mount External Hard Drive using USB Caddy

[Manesh]

I;ve been using Ubuntu (10.xx) for a few months now and am really getting the hang of it.

My NAS drive has now failed.

It is a WD Mybook world edition 1tb with the blue rings.

The drive spins fine and in windows I can see the partitions but I understand the file system is linux based.

Can anyone help as to how I can mount the drive and recover the files using ubuntu / linux.

I have a USB caddy to connect the SATA drive to my laptop.

Any other information let me know.

[Rubberman]

1. Before plugging in external USB enclosure, see what hard drives are recognized on the system: ls /dev/sd?
2. Power up USB enclosure and plug into USB port on system

if system recognizes and automounts partitions, you can access them immediately. If not, then do the following:

3. See what drive letter is assigned to USB drive: ls /dev/sd?
It will be the letter that is not part of the list shown from #1 above. For the purposes of these examples, let's say that the new drive is /dev/sdb
4. Create a mount points, 1 for each partition: sudo mkdir /mnt/nas1 /mnt/nas2 ...
5. Mount partitions: sudo mount /dev/sdb1 /mnt/nas1
etc. (each partition maps to one mount point).
6. Note any errors that occur and report them back to us here.

Any partition that mounted OK should be accessible and you can copy files from them to your system drives. If the drive has file system types that your OS doesn't support, such as jfs or xfs, then you may need to download your kernel source and rebuild it with the missing file system types. If that is the case, we can help you do that as well. I know that I had to do that in order to access jfs and xfs file system types on my CentOS (RHEL) workstation/server, and cifs (samba) file systems on an embedded system I'm working on.

[Manesh]

Hi Rubberman, thanks for the post!

I created 3 mount points named nas1, nas2 and nas3 as per your instructions
the external hard drive was recognised as sdd

When I tried to mount I got the following error message :

ubuntu@ubuntu:~$ sudo mount /dev/sdd1 /mnt/nas1
mount: unknown filesystem type 'linux_raid_member'

hope you can still help!!

Cheers

[Rubberman]

Was there only 1 drive in the device? Post the output from the command fdisk -l /dev/sdd here. If there were 2 drives then you will most likely need to use a software raid tool, such as dmraid, to access the data. It is also possible that if there was only a single drive then they may have used two partitions to get RAID-1 (mirroring) capabilities off the single drive.

[Manesh]

Hi,

There was only 1 HD in the enclosure and also I am quite sure there was no RAID backup on the HD.

Anyway output to the command was :

ubuntu@ubuntu:~$ fdisk -l /dev/sdd
Cannot open /dev/sdd

[Rubberman]

The drive device nodes in /dev are only accessible by root, so preface your command with sudo: sudo fdisk -l /dev/sdd

[Manesh]

Hey Rubberman sorry about that!!!

heres the output : (ps the drive is now sdb)


ubuntu@ubuntu:~$ sudo fdisk -l /dev/sdb

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0009f2d7

Device Boot Start End Blocks Id System
/dev/sdb1 4 369 2939895 fd Linux raid autodetect
/dev/sdb2 370 382 104422+ fd Linux raid autodetect
/dev/sdb3 383 505 987997+ fd Linux raid autodetect
/dev/sdb4 506 121601 972703620 fd Linux raid autodetect

sorry for the delay I have been away for the last few days!

[Rubberman]

Well, you might be able to use the dmraid tool to access the file system. It is also a command that requires the use of sudo on Ubuntu to run. To see what it thinks you have, run the command sudo dmraid -r or sudo /sbin/dmraid -r and post the output here.

[Manesh]

Hi,

outputs from both commands is :

no raid disks

[Rubberman]

Well, this is where I usually go to the vendor's web site and see if there is any recovery software or such. Also, since the device is running linux, the source has to be available as well. If I had the drive in hand I could probably figure a way to access it, but it would take some time and trial&error attempts. In any case, the first thing I would do would be to make a bit-image copy of the drive as well as possibly the file systems on the drive. It is the 4th partition (/dev/sdb4) that likely contains your data, so backup of that partition is your priority. Then you can experiment trying to mount the image as a loop device to see what you can do. It is likely that your kernel doesn't have the appropriate drivers installed for this, but that should be redressable once you determine exactly what type of file system is being used. Once you get the correct file system driver installed, you should be able to mount either the partition directly, or via the image copy, thus gaining access to the data it contains.