What is the sequence of diagnostics I should run on a troubled diskdrive on centos (on AWS)

Question

Running CentOS release 5.4 (Final) on AWS

All of a sudden a disk drive went awol on me.

the device is /dev/sdh ... what do I do to start recovering it?

dmesg results in:

 sdh: unknown partition table

e2fsck /dev/sdh results in

[root@ip-xx-xx-xx-xx ~]# e2fsck /dev/sdh

e2fsck 1.39 (29-May-2006)
Couldn't find ext2 superblock, trying backup blocks...
e2fsck: Bad magic number in super-block while trying to open /dev/sdh

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>

e2fsck -b 8193 /dev/sdh results in

[root@ip-xx-xx-xx-xx ~]#  e2fsck -b 8193 /dev/sdh
e2fsck 1.39 (29-May-2006)
e2fsck: Bad magic number in super-block while trying to open /dev/sdh

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>

Answer 1

first make a backup of the disk (if you have space) with

dd if=/dev/sdh of=your-file.bin

Then you can use some restore utility like testdisk or whatever you want, test smart capabilities, etc.

You can follow the e2fsck instructions and try with e2fsck -b 8193, for example.