[CentOS] server fails to boot GRUB and flashing cursor

Tue Aug 14 13:43:59 UTC 2012
Theo Band <theo.band at greenpeak.com>

On 08/13/2012 11:17 PM, Dan Carl wrote:
> On 8/13/2012 4:07 PM, Les Mikesell wrote:
>> On Mon, Aug 13, 2012 at 2:41 PM, Dan Carl <danc at bluestarshows.com> wrote:
>>>>>       Device Boot      Start         End      Blocks   Id  System
>>>>> /dev/sda1   *           1          13      104391   83  Linux
>>>>> /dev/sda2              14         658     5180962+  82  Linux swap /
>>>>> Solaris
>>>>> /dev/sda3             659        8842    65737980   83  Linux
>>>> You said this had RAID5: what's the o/p of cat /proc/mdstat?\
>>> Its a hardware raid5 perc.
>>> I cannot mount the boot partition sda1.
>>> sda3 mounts fine this is where the OS is.
>>> What to do?
>> What kind of error do you get when you try to mount sda1?   Is it
>> something fsck will fix?   You need to load the kernel and initrd from
>> there.
> #mount -t ext3 /dev/sda1 /mnt/myboot
> mount: wrong fs type, bad option, bad superblock on /dev/sda1,
>         missing codepage or other error
>         In some cases useful info is found in syslog - try
>         dmesg | tail  or so
> I have nothing in my boot directory. Will I have to reload the kernel 
> and grub?
> ran fsck got
> Superblock has an invalid ext3 journal (inode 8).
> Clear<y>?
> Should I select Y?
> Thanks
> Dan

Try to fix, but it will probably not work. It's a bit strange as this
partition is on a raid, so it should be protected by a failing disk just
as the other partitions have survived.
I would boot from a CentosOS rescue CD. It will find your OS and mount
it. Then make a new ext3 fs on /dev/sda1 and mount it under /boot (that
is after the chroot /mnt/sysimage). Copy back the files from a backup if
you have that. If not, a re-install of the kernel (again after chroot)
will place the boot files under /boot/. Then issue a grub-install. It
will copy the needed grub images under /boot/grub and re-create a
grub.conf and a boot loader on /dev/sda etc.