FC2 Grub raid problem, long standing..

[Hans Kristian Rosbach]

One of our newly installed boxes had a diskcrash today,
luckily it was in a 2-disk softraid mirror.

Both disks are sata, and I have successfully exchanged
the defective drive with a new one. Raid has been resynced
ok.

BUT, I cannot boot from any of the two disks since the
boot disk is the one that died.

"grub-install /dev/sda" tells me this:
"/dev/md0 does not have any corresponding BIOS drive"

/dev/md0 is /boot

This bug shows that this is a LONG TIME standing bug:
http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=55484

-HK

[Mogens Kjaer]

Hans Kristian Rosbach wrote:
...
> This bug shows that this is a LONG TIME standing bug:
> http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=55484

I would use lilo instead of grub on a software RAID system.

Mogens

[Hans Kristian Rosbach]

> > This bug shows that this is a LONG TIME standing bug:
> > http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=55484
>
> I would use lilo instead of grub on a software RAID system.

I too would like to use lilo, but unfortunately lilo does
not boot on these computers at all. I think it stops at LI,
but not sure.. Long time since I tried it last.

But why has grub not been fixed for 3+ years?

And what do I do to manually do the grub-install to the disks?
Currently I have no way to boot the box without using the
defective disk to boot into grub menu, then switch sata cable
over to new disk, then boot. It works, but it isn't very nice
in a rack environment =/

-HK

[Jaroslaw Gorny]

On Fri, 03 Sep 2004 15:28:49 +0200
Mogens Kjaer  wrote:
> Hans Kristian Rosbach wrote:
> ...
> > This bug shows that this is a LONG TIME standing bug:
> > http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=55484
>
> I would use lilo instead of grub on a software RAID system.

With all respect: it's a little bit weird advice because Lilo is not
supported very well (You cannot choose lilo during install) and we/you
are promoting grub as default.

Besides, bug is bug, and should be fixed :)
It's not the best idea to advise somebody who found a bug in mozilla to
use konqueror ;)

regards,
Jarek

[Mogens Kjaer]

Jaroslaw Gorny wrote:
...
> With all respect: it's a little bit weird advice because Lilo is not
> supported very well (You cannot choose lilo during install) and we/you
> are promoting grub as default.

You can select lilo during installation if you boot
the installation with "linux lilo".

Mogens

[Jason L Tibbitts III]

> > > > > "HKR" == Hans Kristian Rosbach  writes:

HKR> BUT, I cannot boot from any of the two disks since the boot disk
HKR> is the one that died.

I put GRUB on a floppy to cover this situation.  I've had machines
where the BIOS will simply not boot from any disk except the first, so
I build a GRUB floppy with a menu entry for each disk that finds /boot
and loads the grub.conf from there.

- J<

[Paul Iadonisi]

On Fri, 2004-09-03 at 09:16, Hans Kristian Rosbach wrote:

[snip]
> "grub-install /dev/sda" tells me this:
> "/dev/md0 does not have any corresponding BIOS drive"
>
> /dev/md0 is /boot
>
> This bug shows that this is a LONG TIME standing bug:
> http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=55484

I have a workaround for this.  I usually just edit /etc/mtab and
change the /dev/md* entries with the corresponding /dev/sda*
partitions.  Use lsraid to determine what those are (or look at your
/etc/raidtab).  Then the 'grub-install /dev/sda' should work.  You may
also want to do the same for /dev/sdb.  Don't forget to change them back
to what they were or things might get a little confused (df, for one,
will not show the correct information).  It's a hack, but it's worked
for me.  However, I've never tried booting either of my soft-raid1 disks
without the other one.