Hard disk failure: Additional sense: Unrecovered read error – auto reallocate failed

Last week my laptop suddenly refused to boot any longer. Having configured nothing as root for quite some time, I read:

grub: Error 29: Disk write error

After restarting I got this error again. So I booted my Feisty cdrom and started to inspect the system. There was no obvious error in the first place. Being in a networked environment I decided to save my $HOME using netcat. This worked fine. So in the next step I backuped the root file system. This too worked fine. I finally tried to save another partition containing data of a virtual machine I use with vmplayer.

This failed spitting out a lot of driver error messages, e.g.

Additional sense: Unrecovered read error - auto reallocate failed

But the tar came back finally, saying:

root@ubuntu:/# tar cf - mnt | netcat cheetah 2342
tar: mnt/now2/now2-s004.vmdk: File shrank by 944635904 bytes; padding with zeros

To make a long story short:

After replacing the disk, restoring the filesystems, fixing grub and /etc/fstab my system came up – but with a lot of error messages. I could log in and after a while I found that all links like this one in /sbin were broken:

lrwxrwxrwx 1 root root 7 2008-01-15 14:30 ip -> /bin/ip

Instead I found:

---------- 1 root root 0 2008-01-15 14:50 ip

I fixed a lot of missing links in /sbin, /bin and all of the run level scripts manually. But finally I gave up because I did not find a method to fix the links in a really reliable way (apt, dpkg do not seem to help here – no way to rerun postinstall scripts IMHO).

So finally I reinstalled my laptop. Fortunately all data in $HOME was fine, so I was up and running again rather soon.

Nevertheless: Why failed my backup procedure ?

Solved: See next blog entry

Tags: backup, broken, links, netcat, pitfall, tar