Arch Linux

Dan Forever

Member

Registered: 2010-06-11

Posts: 2

unable to determine major/minor number of root device 'dev/md127p2'

So I've been struggling with this problem for ages and I've finally decided to just bite the bullet and just plead for the mercy of this fine community.
I have a headless raid machine with software raid. The hdds are split into 3 partitions, for /boot, /, and /home respectively. There was an update last year that caused it to switch from md0 I believe to md127 which caused a minor panic but I was eventually able to resolve that.

Now, my current problem: I did a system update a while ago and then when I rebooted I got the error as in the subject title and am kicked out to a recovery console (ramfs:)

I've been messing around with various different bits to try to make it work, and I feel as though I'm close, but I can't quite get there.
When I get into the recovery console now, for instance, if I type "mdassemble", it seems to successfully create my raid array.
If I then type "exit" I'm told "mount: unknown filesystem type 'linux_raid_member'"
but despite that I am able to manually mount my raid partitions from within the ramfs: prompt.

Here is my relevant configuration as it currently stands:

fstab

# /etc/fstab: static file system information
#
# <file system>        <dir>         <type>    <options>          <dump> <pass>
devpts                 /dev/pts      devpts    defaults            0      0
shm                    /dev/shm      tmpfs     nodev,nosuid        0      0

#/dev/cdrom             /media/cd   auto    ro,user,noauto,unhide   0      0
#/dev/dvd               /media/dvd  auto    ro,user,noauto,unhide   0      0
#/dev/fd0               /media/fl   auto    user,noauto             0      0

#/dev/disk/by-id/md-uuid-678ddf85:9561c9dd:0bb2efa1:91eeb404-part1 /boot ext2 defaults 0 1
#/dev/disk/by-id/md-uuid-678ddf85:9561c9dd:0bb2efa1:91eeb404-part2 / ext4 defaults 0 1
#/dev/disk/by-id/md-uuid-678ddf85:9561c9dd:0bb2efa1:91eeb404-part3 /home ext4 defaults 0 1

/dev/md127p1 /boot ext2 defaults 0 1
/dev/md127p2 / ext4 defaults 0 1
/dev/md127p3 /home ext4 defaults 0 1

Grub menu.lst

# (0) Arch Linux
title  Arch Linux
root   (hd0,0)
#kernel /vmlinuz-linux root=/dev/disk/by-id/md-uuid-678ddf85:9561c9dd:0bb2efa1:91eeb404-part2 ro$
kernel /vmlinuz-linux root=/dev/md127p2 ro rootfstype=ext4
initrd /initramfs-linux.img

# (1) Arch Linux
title  Arch Linux Fallback
root   (hd0,0)
#kernel /vmlinuz-linux root=/dev/disk/by-id/md-uuid-678ddf85:9561c9dd:0bb2efa1:91eeb404-part1 ro
kernel /vmlinuz-linux root=/dev/md127p2 ro
initrd /initramfs-linux-fallback.img

The problem happens with both main and fallback images

mkinitcpio.conf HOOKS

HOOKS="base udev sleep autodetect pata scsi sata mdadm filesystems"

The "sleep" line was added at the suggestion of another thread on this forum, but I've since forgotten where.

Some mdadm output:

$ mdadm --detail --scan
ARRAY /dev/md/127_0 metadata=0.90 UUID=678ddf85:9561c9dd:0bb2efa1:91eeb404
$ mdadm --examine --scan
ARRAY /dev/md127 UUID=678ddf85:9561c9dd:0bb2efa1:91eeb404
ARRAY /dev/md125 UUID=2db4dac5:45d2137f:63b9f7d5:ddaa95e5
ARRAY /dev/md125 UUID=bcc0c782:1de31876:c94a1e5a:997ad6a7
ARRAY /dev/md126 UUID=5fe03f03:1392af95:eec0192e:d3c415b5

The results of "mdadm --detail --scan" are currently in /etc/mdadm.conf (I think before I had these problems, I either didn't have an mdadm.conf or it had data that didn't correspond to my actual setup, but either way the system seemed to boot fine).

I don't know what mdadm --examine --scan is doing, as the bottom 3 results have uuids that aren't listed in /dev/disk/by-id