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 4:12 PM, walt <w41ter@×××××.com> wrote:
> > On 09/19/2009 03:38 PM, 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 hate to be the party poop, but I suspect disk hardware failure.
> >
> > Can you use dd to read the raw disk?  e.g.
> > # dd if=/dev/sda of=/tmp/ddout bs=512 count=1024(or whatever)
>
> Hi Walt,
>    Don't worry about it. If it's dead it's dead.
>
>    I've actually managed to make some headway. After fiddling around
> with e2fsck -b 32768 /dev/sda1 the drive is now mountable but running
> e2fsck after a reboot says the drive still has errors:
>
> MacMini ~ # e2fsck /dev/sda1
> e2fsck 1.41.3 (12-Oct-2008)
> /dev/sda1 contains a file system with errors, check forced.
> Pass 1: Checking inodes, blocks, and sizes
> ^C/dev/sda1: e2fsck canceled.
>
> /dev/sda1: ********** WARNING: Filesystem still has errors **********
>
> MacMini ~ #
>
> If I mount the drive I can actually see all the MythTV files and
> amazingly they still seem to play so I don't think the drive is dead.
> I got a few messages about my backup directory being hosed so I
> attempted to delete it. Now the drive mounts but the sizes and things
> are messed up:
>
> MacMini ~ # mount
> /dev/hda4 on / type ext3 (rw,noatime)
> proc on /proc type proc (rw,nosuid,nodev,noexec)
> sysfs on /sys type sysfs (rw,nosuid,nodev,noexec)
> udev on /dev type tmpfs (rw,nosuid,size=10240k,mode=755)
> devpts on /dev/pts type devpts (rw,nosuid,noexec,gid=5,mode=620)
> shm on /dev/shm type tmpfs (rw,noexec,nosuid,nodev)
> usbfs on /proc/bus/usb type usbfs (rw,noexec,nosuid,devmode=0664,devgid=85)
> /dev/sda1 on /video type ext3 (rw)
>
> MacMini ~ # df /video
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/sda1            157566568  -1551528 151114116   -  /video
> MacMini ~ #
>
> MacMini ~ # ls /video/
> 1003_20090531163000.mpg.png  1042_20090611190000.mpg.png
> 1189_20090617183000.mpg.png
> 1003_20090603173000.mpg.png  1042_20090911210000.mpg
> 1189_20090619183000.mpg
> 1003_20090621163000.mpg.png  1042_20090911210000.mpg.png
>
> <SNIP>
>
> 1017_20090817193000.mpg.png  1189_20090617183000.mpg
>  lost+found 1042_20090611170000.mpg.png  1189_20090617183000.mpg.100x75.png
> MacMini ~ #
>
>
> Now, my question is how can I use the file system tools to fix all the
> tables on this drive?
>
> I see Volker is suggesting ddrescue. As it seems I've already lost the
> Windows backup files but have good MYthTV files is there a way to
> repair the disk tables and only end up with the existing Myth files
> and clean tables? I don't have another disk to copy all this stuff to
> and the MacMini is headless and PPC-based so it's difficult to use
> gparted or anything like that.
>
> I think the existing Myth files are possibly small enough that I could
> store them temporarily on the Mac while I rebuild the USB drive.
>
> Thanks,
> Mark
>

seriously, I think you should try to get off everything you want to keep - and 
then replace the disk with a new one. If a disk starts throwing block errors 
it will only become worse. Don't worry about 'repairing' the file system as 
long as there is hardware damage. Try to get off the disk as much as possible - 
and then scrap it.