Corrupt Superblock on /home

[Craig White]

On Thu, 2006-02-09 at 16:20 -0500, Nancy Merckle wrote:
> Hi,
> 
> I still haven't been able to boot up my FC4 box, beyond repair mode 
> without a live distro CD.  The attempt gave me errors on /home with 
> something along the lines of (from my notes):
>  	Buffer I/O error on device hdb1
>  	/dev/hdb1 reaad failed after 0 of 2048 at 0
>  	No Volume group found
> 
> Using the live distro, I was able to determine that all of hdba will mount 
> (except hdba3 which is swap space) along with hdb2, my /data directory. 
> All mounted and I could see the files on /dev/hda1 (/boot), /dev/hda2 
> (/1), /dev/hda4 (/data1), /dev/sda1 (usb drive) and /dev/hdb2 (/data). 
> The plan was to have OS files on hda and most/all data on hdb so that if 
> the OS disk got hosed data wouldn't be lost.
> 
> I tried "mount /dev/hdb1 -vt ext3 /mnt/hdb1" and got
> 
> mount: wrong fs type, bad option, bad superblock on /dev/hdb1,
>         missing codepage or other error
>         In some cases useful info is found in syslog - try
>         dmesg | tail  or so
> 
> root at 2[root]# dmesg | tail
> Buffer I/O error on device hdb1, logical block 7
> hdb: dma_intr: status=0x51 { DriveReady SeekComplete Error }
> hdb: dma_intr: error=0x40 { UncorrectableError }, LBAsect=63, high=0,
> low=63, sector=63
> ide: failed opcode was: unknown
> end_request: I/O error, dev hdb, sector 63
> FAT: unable to read boot sector
> hdb: dma_intr: status=0x51 { DriveReady SeekComplete Error }
> hdb: dma_intr: error=0x40 { UncorrectableError }, LBAsect=65, high=0,
> low=65, sector=65
> ide: failed opcode was: unknown
> end_request: I/O error, dev hdb, sector 65
> EXT3-fs: unable to read superblock
> 
> I can't remember the command I used next, but I wound up getting the 
> result of a "bad magic number in superblock"
> 
> When I went back to repair mode, the file system start up gives clean 
> report on /1, /boot, /data and /data1.
> 
> I tried e3fsck, e2fsck with both the -cc and -t options followed by 
> similar commands with plain fsck.  This last try at fsck -t ext3 /dev/hdb1 
> gave me "Attempt to read block from file system resulting in short read 
> while trying to open /dev/hdb1. Could this be a zero-length partition? 
> I've even tried these commands on /dev/hdb and all I got was a little 
> longer wait time before the bad news.
> 
> I'm getting to the end of everything I can think of to do.  My next bright 
> idea is to try to change the partition names from /data1 to /home and 
> making hdb1 /<something else> to verify that the OS is still working and 
> perhaps get me back and running (although at a diminished capacity) while 
> I learn and research.  I've even toyed with the idea of installing windoze 
> on the /data1 drive to see if I could get some sort of windoze disk data 
> rescue software to retreive what I could of hdb1.  Unless there has been 
> some magic discovery of a software retrival package for linux since the 
> last time it was discussed on this list.
> 
> Can someone please help me save my /home directory or is it totally hosed?
> 
----
Are you absolutely certain that /dev/hdb1 was your /home ?

when you are booted with live cd...

try

fdisk -l /dev/hdb

and that should give a list of partitions that it recognizes on the
disk. Perhaps that isn't your /home after all...that would seem to be a
less than logical place to put /home.

Craig