Intel Matrix RAID metadata messed up by geom
Benny Goemans
benny.goemans at belgacom.net
Fri Apr 25 13:07:01 UTC 2014
(I originally sent this to the geom mailinglist, but I assume that list
isn't meant for user questions; I've also added some more info)
Hi all,
First some background:
I'm running 2 rather big raid (well, software raid) arrays, one RAID 0
and one RAID 5. Up to now this didn't pose much problems, aside from the
occasional rebuilding for which I needed to boot my fallback windows OS.
I was happy with this, but since I'm lagging behind this much in version
(8- will soon disappear) I assumed that I could at least try upgrading
to 10 and see what happens. So, I did:
* used freebsd-update to get updates, merge and install
* rebooted into BSD 10 kernel
* I see messages from GEOM passing by, noticing my raid arrays
* I get warnings about read-only filesystems and I realise that geom
doesn't support writing to ICH RAID 5 arrays (which I read when I wanted
to upgrade to 9, but seemed to have forgotten)
I figure, no harm done, I'll just boot a 8.4 disk and reinstall the
kernel. So I reboot ... only to find out that my drives show up as
INCOMPATIBLE in the ICH configuration utility. I'm assuming that GEOM
decided to overwrite critical metadata with a version that my
motherboard doesn't support.
I never ran any geom tools, never saw a warning in the boot which would
have prompted me to abort. It just did.
So, I have two questions:
1a) isn't this a bug? I'm assuming that GEOM shouldn't at least
overwrite metadata without allowing the user to abort, especially not
with a newer version that might not be supported anymore
1b) does this also happen when booting the live cd? if it does, it
doesn't feel right
2) is there anyone out there who can help me get this meta data back to
a version my mainboard supports? I really need this system up and
running again (as it's my main pc) without having to reinstall
everything, which would take ages. I do have backups of most critical
data, but I'd still like to have the non/less-critical data as well.
Some extra info:
mainboard: Asus P5WDG 2 WS, with latest (official) 0805 bios
ICH: 5.1.2, ICH7R
I can boot the system with a BSD 10 memdisk and access the data on the
BSD partitions, so it's not gone. For the ntfs partitions I'm still
looking for a solution, but as I said I'd rather get the system up and
running again than try to backup everything that I need and rebuild. The
risk that I'm forgetting something is simply too big.
What I'm currently doing/trying:
* backing up as much as I can
* trying to find more information of the metadata written by geom or the
ICH, without much luck
** I figure the changes won't be huge between what GEOM has written and
what the original data was; if I find a datasheet I might try to fix it
manually
* figuring out a way to restore the correct metadata without trying to
understand geom source code, as this is _way_ over my skill set; it
would likely take years for me to figure it out
* checking out unofficial bios'es for my mainboard that may or may not
have a more recent ICH on board; last resort only though as these may
put me off even worse (with no more access to these disks at all)
Kind regards,
Benny Goemans
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