[PATCH] Software RAID (fakeraid) support for Linux device mapper

[Raphael Bossek]

Hi folks,

I'm using Debian GNU/Linux "squeeze/sid" with Linux
2.6.32-5-686-bigmem were my two harddisks are configured in Software
RAID (aka faikraid).
Because faikraid did not work for me especialy since udev version 158
where /dev/mapper/pdc_* are symlinked to /dev/dm-* nodes I tried
myself in coding GRUB and fixed all my issues with the applied patches
(based on 1.98 bzr 20100710 as provided by Debian; 1.98+20100710-1).

1) zcat bossekr-mdraidorlvm.patch.gz | patch -p1
2) zcat bossekr-fakeraid.patch | patch -p1

The solution was to improve the support for /dev/dm- device nodes.

Greetings,
Raphael Bossek

Here some additional information about my setup:

$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-2.6.32-5-686-bigmem
root=UUID=081cf388-6820-4843-a4d5-9f0d4be424ef ro quiet splash

$ cat /proc/self/mountinfo
14 19 0:0 / /sys rw,nosuid,nodev,noexec,relatime - sysfs none rw
15 19 0:3 / /proc rw,nosuid,nodev,noexec,relatime - proc none rw
16 19 0:5 / /dev rw,relatime - devtmpfs none
rw,size=2064088k,nr_inodes=212971,mode=755
17 16 0:11 / /dev/pts rw,nosuid,noexec,relatime - devpts none
rw,gid=5,mode=620,ptmxmode=000
19 1 254:3 / / rw,relatime - ext4
/dev/disk/by-uuid/081cf388-6820-4843-a4d5-9f0d4be424ef
rw,errors=remount-ro,barrier=1,data=ordered
20 19 0:15 / /lib/init/rw rw,nosuid,relatime - tmpfs tmpfs rw,mode=755
21 16 0:16 / /dev/shm rw,nosuid,nodev,relatime - tmpfs tmpfs rw
23 19 0:17 / /var/lib/nfs/rpc_pipefs rw,relatime - rpc_pipefs rpc_pipefs rw
24 14 0:18 / /sys/fs/fuse/connections rw,relatime - fusectl fusectl rw
25 15 0:19 / /proc/fs/nfsd rw,relatime - nfsd nfsd rw
26 15 0:20 / /proc/sys/fs/binfmt_misc rw,nosuid,nodev,noexec,relatime
- binfmt_misc binfmt_misc rw

$ ls -1l /dev/mapper/
crw------- 1 root root 10, 59 Jul 14 12:56 control
lrwxrwxrwx 1 root root      7 Jul 14 12:56 pdc_fcgchefh -> ../dm-0
lrwxrwxrwx 1 root root      7 Jul 14 12:56 pdc_fcgchefh1 -> ../dm-1
lrwxrwxrwx 1 root root      7 Jul 14 12:56 pdc_fcgchefh2 -> ../dm-2
lrwxrwxrwx 1 root root      7 Jul 14 12:56 pdc_fcgchefh3 -> ../dm-3

$ ls -1l /dev/dm-*
brw-rw---- 1 root disk 254, 0 14. Jul 11:45 /dev/dm-0
brw-rw---- 1 root disk 254, 1 14. Jul 10:56 /dev/dm-1
brw-rw---- 1 root disk 254, 2 14. Jul 10:56 /dev/dm-2
brw-rw---- 1 root disk 254, 3 14. Jul 10:56 /dev/dm-3

bossekr-fakeraid.patch.gz
Description: GNU Zip compressed data

bossekr-mdraidorlvm.patch.gz
Description: GNU Zip compressed data