Bug#432154: LVM not working when *any* md array degraded

[Robert Millan]

Sorry for the late reply.

On Sun, Jul 08, 2007 at 11:07:41AM +1000, Trent Buck wrote:
> 
> Note that / and /boot are on LVM, on RAID1.  While grub-probe does not
> correctly detect the necessary modules (pc lvm raid ext2), manually
> creating core.img and installing it allows grub to boot directly from
> (ares-root).

Please try the latest version.  Does grub-probe detect the correct modules
now?

If not, please tell me how can I reproduce this on a normal PC.  I have
tried to setup /boot as LVM in D-I, but it won't let me.

> lsmod reported that the raid and lvm modules were definitely loaded.
> Attempting to do "insmod normal" resulted in the "error: unknown
> device."  Running the command "ls" printed a number of (mdX), (hdX)
> and (hdX,Y) devices, but no LVM devices -- that is, (ares-X).
> 
> I COULD NOT WORK OUT HOW TO GET GRUB PAST THE RESCUE STAGE.

Does this still apply?  Was the "pc" module listed by lsmod?  What happens
if you do "set debug=all" and then insmod normal?  Can you obtain the full
log via serial cable?  (see http://grub.enbug.org/HowToDebug)

> Since md3 had absolutely nothing to do with md0 and ares-root -- it
> wasn't even on the same disks -- my initial suspicion is that grub
> cannot currently boot from an LVM-on-RAID1 /boot

There are known problems with this setup;  unfortunately, I haven't figured
out how to reproduce it.  Please provide a guideline for a simple test case
if you can.

> if there are *any*
> degraded arrays on the system.

What is a degraded array?

> While the array was degraded, "grub-probe /" gave the error "unknown
> device" (IIRC), and update-grub terminates unsuccessfully.  When all
> arrays working, "grub-probe /" gives the error "Unknown partition
> map", and update-grub terminates successfully.  In both cases
> 'grub-install (hd0)' terminates unsuccessfully.

Please can you try with latest grub-probe?  Also, add -v flag for verbose
output.

> Finally, a very big thanks to the maintainer for holding my hand in
> #grub on freenode for a couple of hours while I raged at rescue mode,
> etc.

I did that?  Ah well, you're welcome ;-)

-- 
Robert Millan

<GPLv2> I know my rights; I want my phone call!
<DRM> What use is a phone call… if you are unable to speak?
(as seen on /.)