Error mounting SCSI drive on Ubuntu 14.04 server.

**Geza_Fischer** · March 31st, 2015

I'm trying to mount a SCSI Drive on my Ubuntu 14.04 server.
To mount I entered this in the Terminal:
geza@Server1:~$ sudo mount -t ext4 /dev/sdb /media/sdb
mount: wrong fs type, bad option, bad superblock on /dev/sdb,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
Then I did a fsck:
geza@Server1:~$ sudo fsck.ext4 /dev/sdb
e2fsck 1.42.9 (4-Feb-2014)
ext2fs_open2: Bad magic number in super-block
fsck.ext4: Superblock invalid, trying backup blocks...
fsck.ext4: Bad magic number in super-block while trying to open /dev/sdb

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem. If the device is valid and it really contains an ext2/ext3/ext4
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>
or
e2fsck -b 32768 <device>

geza@Server1:~$
I posted this on Askubuntu.com and they told me to do a fdisk -l /dev/sdb .

It couldn't find the /dev/sdb disk it could only find the /dev/sda disk which is the other 2 drives on the server configured with RAID 1.

What should I do?

Thanks
Geza

**darkod** · March 31st, 2015

First, you can't mount the disk directly as you are trying to. Your command tries to mount /dev/sdb which is the whole hdd. You mount partitions, and you have to create the ext4 filesystem before that. It doesn't simply mount when not created.

So, you need to use parted or fdisk or which ever partitioning tool you are familiar with to make partitions on /dev/sdb, then format those partitions, and then try to mount the partitions (or a single partition on the whole disk, if you want that).

If ubuntu sees only sda and not the sdb disk, then maybe it doesn't have the drivers to read the scsi adapter (and the disk attached to it), etc... So you need to look into that matter first because you can't use the disk until you can see it.

**Geza_Fischer** · April 1st, 2015

The drive has an ext4 file system set up on it already. And it has to have the drivers because it was working a few weeks ago.

Thanks
Geza

**darkod** · April 1st, 2015

Ok. But you are still trying to mount it wrong. /dev/sdb is the whole disk. To mount a specific partition you use the partition number at the end, like /dev/sdb1. Also for ext4 you don't need to use the -t option. You can simply use:

Code:

sudo mount /dev/sdb1 /media/sdb

Also /media is usually used by the system for auto temporary mounts. You can create any mount point you want and use that instead of /media.

To see all disks and partitions show us the output of:

Code:

sudo parted -l (that is small L)

That will help figure out which partitions you have and their filesystem.

**Geza_Fischer** · April 1st, 2015

See the problem is that Ubuntu doesn't recognize the disk. Here is the output of sudo parted -l :

Code:

geza@Server1:~$ sudo parted -l
[sudo] password for geza:
no talloc stackframe at ../source3/param/loadparm.c:4864, leaking memory
Model: MegaRAID LD 0 RAID1 286G (scsi)
Disk /dev/sda: 300GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number  Start   End     Size    Type      File system     Flags
 1      1049kB  30.0GB  30.0GB  primary   ext4            boot
 2      30.0GB  300GB   270GB   extended
 5      30.0GB  298GB   268GB   logical   ext4
 6      298GB   300GB   2145MB  logical   linux-swap(v1)

Error: /dev/sdb: unrecognised disk label
geza@Server1:~$

Thanks

Geza

**darkod** · April 1st, 2015

Well it seems it knows sdb is there but can't read it. Maybe the disk got faulty/died or something?

**Geza_Fischer** · April 1st, 2015

I'm not sure. It's pretty old. Is there a way to recover it?

Thanks
Geza

**darkod** · April 2nd, 2015

Unfortunately if it doesn't read the disk correctly it would be very difficult to reach the data. Do you have a backup? If you do you can simply buy a new disk and put the data back.

**Geza_Fischer** · April 3rd, 2015

No I don't have a backup. That drive was the backup and that's why I was trying to move it to the 2 new drives I just got. The other old drive corrupted 1 month ago. Is it possible to repair it from the backup Superblocks? I tried a few tutorials on the internet for doing an # fdisk -b (superblock) /dev/sdb but every time I did it, it didn't put out a response. I tried all the backup SB's. Anything else I can do?

Thanks
Geza