Re: [gentoo-user] Re: USB drive dead? (Commands to check?)

[Volker Armin Hemmann]

On Sonntag 20 September 2009, Mark Knecht wrote:
> On Sat, Sep 19, 2009 at 3:21 PM, Mark Knecht <markknecht@×××××.com> wrote:
> > Hi,
> >   I seem to have lost an external USB drive I've been using on my
> > MythTV backend server for video storage. What commands can I try to
> > get it to wake up or at least show me what's working and what isn't?
> > The drive shows under fdisk /dev/sda. I can see the large partition,
> > and it seems to be the right size, according to fdisk anyway, but I
> > cannot mount it using mount, and so far I cannot get e2fsck to do
> > anything. Both of these fail:
> >
> >
> > mount -t ext2 /dev/sda1 /video
> > mount -t ext3 /dev/sda1 /video
> >
> >   I have power cycled the drive and I've rebooted the MacMini. Nothing
> > changed.
> >
> > Thanks in advance,
> > Mark
> >
> > MacMini ~ # fdisk /dev/sda
> >
> > The number of cylinders for this disk is set to 19929.
> > There is nothing wrong with that, but this is larger than 1024,
> > and could in certain setups cause problems with:
> > 1) software that runs at boot time (e.g., old versions of LILO)
> > 2) booting and partitioning software from other OSs
> >   (e.g., DOS FDISK, OS/2 FDISK)
> >
> > Command (m for help): p
> >
> > Disk /dev/sda: 163.9 GB, 163928604672 bytes
> > 255 heads, 63 sectors/track, 19929 cylinders
> > Units = cylinders of 16065 * 512 = 8225280 bytes
> > Disk identifier: 0xa9b5c6b5
> >
> >   Device Boot      Start         End      Blocks   Id  System
> > /dev/sda1               1       19929   160079661   83  Linux
> >
> > Command (m for help):
> >
> >
> >
> > MacMini ~ # df
> > Filesystem           1K-blocks      Used Available Use% Mounted on
> > /dev/hda4             75890040  37169416  34865560  52% /
> > udev                     10240       156     10084   2% /dev
> > shm                     257396         0    257396   0% /dev/shm
> > MacMini ~ # fsck -t ext3 /dev/sda
> > fsck 1.41.3 (12-Oct-2008)
> > e2fsck 1.41.3 (12-Oct-2008)
> > fsck.ext3: Superblock invalid, trying backup blocks...
> > fsck.ext3: Bad magic number in super-block while trying to open /dev/sda
> >
> > 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>
> >
> > MacMini ~ # e2fsck -b 8193 /dev/sda
> > e2fsck 1.41.3 (12-Oct-2008)
> > e2fsck: Bad magic number in super-block while trying to open /dev/sda
> >
> > 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>
> >
> > MacMini ~ # fsck -t ext3 /dev/sda1
> > fsck 1.41.3 (12-Oct-2008)
> > e2fsck 1.41.3 (12-Oct-2008)
> > fsck.ext3: Attempt to read block from filesystem resulted in short
> > read while tr            ying to open /dev/sda1
> > Could this be a zero-length partition?
> > MacMini ~ # e2fsck -b 8193 /dev/sda1
> > e2fsck 1.41.3 (12-Oct-2008)
> > e2fsck: Bad magic number in super-block while trying to open /dev/sda1
> >
> > 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>
> >
> > MacMini ~ # e2fsck -b 8193 /dev/sda
> > e2fsck 1.41.3 (12-Oct-2008)
> > e2fsck: Bad magic number in super-block while trying to open /dev/sda
> >
> > 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>
> >
> > MacMini ~ #
>
> A little more info:
>
> Buffer I/O error on device sda, logical block 12
> sd 0:0:0:0: [sda] Result: hostbyte=0x00 driverbyte=0x08
> sd 0:0:0:0: [sda] Sense Key : 0x3 [current]
> sd 0:0:0:0: [sda] ASC=0x4b ASCQ=0x0
> end_request: I/O error, dev sda, sector 96
> Buffer I/O error on device sda, logical block 12
> sd 0:0:0:0: [sda] Result: hostbyte=0x00 driverbyte=0x08
> sd 0:0:0:0: [sda] Sense Key : 0x3 [current]
> sd 0:0:0:0: [sda] ASC=0x4b ASCQ=0x0
> end_request: I/O error, dev sda, sector 96
> Buffer I/O error on device sda, logical block 12
> sd 0:0:0:0: [sda] Result: hostbyte=0x00 driverbyte=0x08
> sd 0:0:0:0: [sda] Sense Key : 0x3 [current]
> sd 0:0:0:0: [sda] ASC=0x4b ASCQ=0x0
> end_request: I/O error, dev sda, sector 96
>
> MacMini ~ # fsck -t ext3 /dev/sda1
> fsck 1.41.3 (12-Oct-2008)
> e2fsck 1.41.3 (12-Oct-2008)
> fsck.ext3: Attempt to read block from filesystem resulted in short
> read while trying to open /dev/sda1
> Could this be a zero-length partition?
> MacMini ~ #
>
>
> end_request: I/O error, dev sda, sector 95
> __ratelimit: 58 callbacks suppressed
> Buffer I/O error on device sda1, logical block 16
> Buffer I/O error on device sda1, logical block 17
> Buffer I/O error on device sda1, logical block 18
> Buffer I/O error on device sda1, logical block 19
> Buffer I/O error on device sda1, logical block 20
> Buffer I/O error on device sda1, logical block 21
> Buffer I/O error on device sda1, logical block 22
> Buffer I/O error on device sda1, logical block 23
> Buffer I/O error on device sda1, logical block 24
> Buffer I/O error on device sda1, logical block 25
> sd 0:0:0:0: [sda] Result: hostbyte=0x00 driverbyte=0x08
> sd 0:0:0:0: [sda] Sense Key : 0x3 [current]
> sd 0:0:0:0: [sda] ASC=0x4b ASCQ=0x0
> end_request: I/O error, dev sda, sector 95
> __ratelimit: 86 callbacks suppressed
> Buffer I/O error on device sda1, logical block 16
> Buffer I/O error on device sda1, logical block 17
> Buffer I/O error on device sda1, logical block 18
> Buffer I/O error on device sda1, logical block 19
> Buffer I/O error on device sda1, logical block 20
> Buffer I/O error on device sda1, logical block 21
> Buffer I/O error on device sda1, logical block 22
> Buffer I/O error on device sda1, logical block 23
> Buffer I/O error on device sda1, logical block 24
> Buffer I/O error on device sda1, logical block 25
> MacMini ~ #
>
>
> I could try reinstalling the file system but I had a few backups on
> this drive for other systems. (non-critical, but possibly useful) I'd
> like to be sure I cannot recover them before I blow everything away.
>
> Thanks,
> Mark
>

you might be lucky and able to use smartctl on that device. Sadly most usb 
converters don't support smart even when the drive does.

That could tell you some more, but a quick glance says:

your drive is hosed. 
Block errors... ugh... maybe the heads had a bit of platter contact.

You can try using magicrescue - or even better photorec.

they won't repair your filesystems - but they might be able to get the data off 
you are after.

Glück Auf
Volker