[CentOS] Using CentOS Live CD to recover trashed RHEL system

Fri Jun 25 16:20:05 UTC 2010
m.roth at 5-cent.us <m.roth at 5-cent.us>

drew einhorn wrote:
> On Thu, Jun 24, 2010 at 7:53 PM, Joseph L. Casale
> <jcasale at activenetwerx.com
>> wrote:
>
>> > The part I'm not certain about is the grub voodoo to get the system to
>> > boot to the lvm with the restored root file system.
<snip>
> The seems to be something here that I don't get!
<snip>
>
> I do have a level 0 dump of /boot in addition to the level 0 dump of /
>
> I can restore the contents of /boot and / but things will proabably not
> end
> up in the same physical sectors.  Running grub the right way should update
> parameter for the boot loader to first tranfer control to the right place
> in /boot which then accesses the right filesytem in the right PV/LV
>
> You seem to be saying that all I need to to do is tweak /etc/fstab in the
> root file system in the new pvn/lvm.
>
> Actually as I try to explain my current understanding things are getting
> clearer.
>
> It seems to me that at least one more step is required.   getting a proper
<snip>

I think I know what you need to do: once you've got the /boot restored,
and the LVM mounted (the liveCD ought to let you do that), then you need
to chroot to the mounted fixed drives, and
grub-install /dev/sda
(or whatever it is). Then you may want to edit /boot/grub/device.map to
only show (hd0,0). And DON'T FORGET to create /boot/grub/grub.conf!

That should do it.

          mark "just did it last week"