Arch Linux

Thralas

Member

Registered: 2007-06-26

Posts: 32

RAID 1 on root - kernel panic

Hello,

I'm trying to reinstall arch, using the following setup:

- /dev/sda contains old install, I'll mount it later to copy things over. Thus not used for the new install.
- /dev/sdb will be used for the install. Divided into sdb1, sdb2, sdb3 (boot, swap, root) all raid1 (sda will later be used to mirror sdb's contents on).
- /dev/sdc, /dev/sdd, /dev/sde contain an existing raid5 array.

Mountpoints:
/dev/sdb1 on /dev/md1 (boot)
/dev/sdb2 on /dev/md2 (swap)
/dev/sdb3 on /dev/md0 (root)

I successfully created the raid partitions, and continued installing Arch:
- Saved my mdadm config to /etc/mdadm.conf
- Added 'raid' to mkinitcpio.conf before filesystems and added 'raid1' to modules (the latter was a desperate attempt to get it working)
- Added a 'md=0,/dev/sdb3' line to 'kernel' in my grub config (also added this to mkinitcpio.conf, not sure if it's even required)

I continued installing arch and rebooted, however I get a kernel panic because (unable to mount md0). A few lines up I see md trying to configure md0 from /dev/sdb3 (as it should), however it outputs 'md: personality for level 1 is not loaded!' followed by 'md: starting md0 failed'.

Any ideas?

daf666

Member

Registered: 2007-04-08

Posts: 470

Website

Re: RAID 1 on root - kernel panic

Hi, maybe this can help: http://bbs.archlinux.org/viewtopic.php?id=37872

Regards
daf666

Thralas

Member

Registered: 2007-06-26

Posts: 32

Re: RAID 1 on root - kernel panic

I've read that topic, among others and the tutorial on our own & Gentoo's wiki. Problem is that I've exactly done the kernel line / mkinitcpio bit like those, and yet it refuses to work. Interesting detail: using 'arch root=/dev/md0 md=0,/dev/sdb3' with the 2008.10.2 installer CD allows me to boot just fine (it has a 2.6.22 kernel though). So it has to be somewhere in my mkinitcpio.conf?

mkinitcpio.conf: http://rafb.net/p/Ukuzk176.html

Thralas

Member

Registered: 2007-06-26

Posts: 32

Re: RAID 1 on root - kernel panic

I've solved the problem by reinstalling and recreating the RAID arrays, this time also adding /dev/sda to the array instead of using a degraded array with just /dev/sdb. Sadly I still do not know why it didn't work with a single device..

thetrivialstuff

Member

Registered: 2006-05-10

Posts: 191

Re: RAID 1 on root - kernel panic

I know I've booted successfully with degraded arrays before; I think you might have to specify the devices like this:

md=0,/dev/sdb3,missing

Not positive on that though (it's been a while since I've had to do it).

~Felix.