Re: Bug#597563: grub-common: grub-probe segfaults scanning lvm devices

As was recommended I forward the remaining part to linux-raid mailing list.
In short: on his system mdraid, raid5, 4 devices, metadata (presumably)
0.90, two devices have index 0.
If such situation is valid please advice me on how such situation should
be handled.
@Matthew: could you supply mdadm -Q outputput and *last* 64K of every disk?
On 01/08/2011 05:08 AM, Matthew Gabeler-Lee wrote:

On Fri, 7 Jan 2011, Vladimir 'φ-coder/phcoder' Serbinenko wrote:

quoted

I believe it to be a problem with raid5. Could you try the latest
upstream? If problem persists I would need following dumps:
dd if=/dev/sd[abcd]3 of=[abcd].img bs=1024 count=64
dd if=/dev/md2 of=2.img bs=1024 count=64
grub-fstest -c 4 /dev/sda3 /dev/sdb3 /dev/sdc3 /dev/sdd3 hex -l
'(md2)+128' > g2.img

OK, built grub from latest bzr trunk.

From my past workarounds, I effectively have a list of all the
invocations of grub-probe that grub-install/grub-setup runs on my
system.  Most of those work fine now.  The only thing that isn't fine
is that most invocations spit out a message "error: found two disks
with the number 0" but give a correct answer and exit successfully.

If I run grub-probe with enough --verbose arguments, then that message
gets this context:

grub-core/disk/raid.c:699: Scanning for RAID devices on disk hd2
grub-core/kern/disk.c:245: Opening `hd2'...
./grub-probe: info: the size of hd2 is 1465149168.
error: found two disks with the number 0.
grub-core/kern/disk.c:330: Closing `hd2'.

So, it seems maybe you're right that there's something funky with the
raid5.  The outputs you requested are attached.  The grub-fstest
invocation complained that -l is not a valid option, I hope the output
without it is still what you want / need.  I included the full output
of one of the complaining grub-probe invocations too, on the guess
that it might be helpful.

FWIW, the raid5 array in question has had every disk swapped at least
once in its life span, including from growing from 3 to 4 disks, and
from smaller to larger disks, not to mention one or two disk failures
along the way.

-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko