[CentOS] Superblock Problem

[m.roth at 5-cent.us]

Guy Boisvert wrote:
>   Hi all,
>
> After rebooting my CentOS 5.5 server, i have the following message:
>
> ==================================
> Red Hat nash version 5.1.19.6 starting
> EXT3-fs: unable to read superblock
> mount: error mounting /dev/root on /sysroot as ext3: invalid argument
> setuproot: moving /root failed: No such file or directory
> setuproot: error mounting /proc: No such file or directory
> setuproot: error mounting /sys: No such file or directory
> switchroot: mount failed: no such file or directory
> Kernel panic - not syncing: Attempted to kill init!
>
>
> I booted the server (rescue mode) with CentOS 5.4 x64 i have used to
> initially install it.  It recognizes all the RAID1 partitions i have.
>
> cat /mnt/sysimage/proc/mdstat
> ============================
> md3 : active raid1 sdb2[1] sda2[0]
>        2048192 blocks [2/2] [UU]
>
> md1 : active raid1 sdb3[1] sda3[0]
>        486134848 blocks [2/2] [UU]
>
> md0 : active raid1 sdb1[0] sda1[1]
>        200704 blocks [2/2] [UU]
>
> unused devices: <none>
>
>
> cat /mnt/sysimage/boot/grub/menu.lst
> ===================================
> # grub.conf generated by anaconda
> #
> # Note that you do not have to rerun grub after making changes to this
> file
> # NOTICE:  You have a /boot partition.  This means that
> #          all kernel and initrd paths are relative to /boot/, eg.
> #          root (hd0,0)
> #          kernel /vmlinuz-version ro root=/dev/md1
> #          initrd /initrd-version.img
> #boot=/dev/md0
> default=0
> timeout=5
> splashimage=(hd0,0)/grub/splash.xpm.gz
> hiddenmenu
> title CentOS (2.6.18-164.10.1.el5xen)
>          root (hd0,0)
>          kernel /xen.gz-2.6.18-164.10.1.el5
>          module /vmlinuz-2.6.18-164.10.1.el5xen ro root=/dev/md1 rhgb
> quiet
>          module /initrd-2.6.18-164.10.1.el5xen.img
> title CentOS (2.6.18-164.10.1.el5)
>          root (hd0,0)
>          kernel /vmlinuz-2.6.18-164.10.1.el5 ro root=/dev/md1 rhgb quiet
>          initrd /initrd-2.6.18-164.10.1.el5.img
<snip>
First, have you tried booting with the second one, or do you require xen?

Second, I find it odd, since the kernel I have with 5.5 is
2.6.18-194.3.1.el5 (well, the initial install gave me 2.6.18-194.el5, but
this was the first upgrade).

Finally, it's almost as though grub were not correctly installed - have
you checked /boot/grub/device.map?

        mark