[Tfug] Repairing grub after array rebuild

[Kramer Lee]

It seems that the drive replaced is now designated /dev/md0

a raid designation.

And then grub-install can't find the file system on md0.

I don't know how you are going to boot this, unless you are using a
live CD/DVD, so you can run

fdisk -l

and see what your disk has as a designation.  hopefully it is /dev/md0

Maybe you can use the Super Grub Boot disk and get up far enough to
install grub.  Installing grub on a raid array is something I have
never done.

On 3/11/13, Timothy D. Lenz <tlenz at vorgon.com> wrote:
> Got the warranty replacement drive installed and got the 3 mirror arrays
> restored. But the last step I had in my notes to make the drive bootable
> didn't seem to work. I build raid into the kernel so it can boot right
> from ether drive if the other fails. My notes from an IRC chat:
>
> ---------------------------------------------------------------------
> [14:02] <Jordan_U> Vorg: No. First, what is the output of grub-install
> --version?
> [14:02] <Vorg>  (GNU GRUB 1.98~20100115-1)
> [14:04] <Jordan_U> Vorg: Ok, then run "grub-install /dev/sda &&
> grub-install /dev/sdb" (where sda and sdb are the members of the array)
> [14:05] <Vorg> I haven't added sdb to the array yet, ok, to do this
> before adding it in?
> [14:06] <Vorg> sda is the current remaining drive from the array and sdb
> is the new one. Just don't want to screw up the old one and have nothing
> working
> [14:06] <Jordan_U> Vorg: You should add sdb to the array first.
> ---------------------------------------------------------------------
>
> I have done this before, but this time I got some kind of error:
>
> ---------------------------------------------------------------------
> vorg at x64VDR:~$ su
> Password:
> x64VDR:/home/vorg# grub-install /dev/sda && grub-install /dev/sdb
> /usr/sbin/grub-probe: error: no such disk.
> Auto-detection of a filesystem of /dev/md0 failed.
> Please report this together with the output of "/usr/sbin/grub-probe
> --device-map=/boot/grub/devi             ce.map --target=fs -v
> /boot/grub" to <bug-grub at gnu.org>
> x64VDR:/home/vorg# exit
> exit
> vorg at x64VDR:~$
> ---------------------------------------------------------------------
>
>   The drive replaced is sda.
>
> _______________________________________________
> Tucson Free Unix Group - tfug at tfug.org
> Subscription Options:
> http://www.tfug.org/mailman/listinfo/tfug_tfug.org
>