Re: root (/) on software raid
On Tue, Aug 23, 2005 at 09:42:15AM -0600, Jamin W. Collins wrote:
> I've managed to enable software raid on one of my systems. Four
> different arrays built as follows:
>
> /dev/md0: (/boot)
> - /dev/hda1 & /dev/hdc1
>
> /dev/md1: (/var/log)
> - /dev/hda6 & /dev/hdc6
>
> /dev/md2: (/)
> - /dev/hda7 & /dev/hdc7
>
> /dev/md3: (/opt/backup)
> - /dev/hda8 & /dev/hdc8
>
> Three of the four come up perfectly after reboot (md0, md1, & md3). The
> problem is with md2. After every reboot it's degraded with only hdc7 as
> a member. I can manually re-add hda7 and it syncs without error and
> works fine until the next reboot. But I'd like to correct this so this
> isn't necessary.
>
> I'm using grub as my boot loader and the following is the entry being
> loaded on startup:
>
> title Debian GNU/Linux, kernel 2.6.11-1-386
> root (hd0,0)
> kernel /vmlinuz-2.6.11-1-386 root=/dev/md2 ro
> initrd /initrd.img-2.6.11-1-386
> savedefault
> boot
>
> The system is running sarge, with the exception of the kernel. I'd be
> happy to provide any further information that may be helpful.
>
If you check the rootraiddoc.97.html, usually
/usr/share/doc/mdadm/rootraiddoc.97.html or via
http://alioth.debian.org/projects/rootraiddoc
Down around section 8, just before the appendix, there is this little
blurb:
When using mdadm, mkinitrd will only detect disks in the array that are
running at the time of execution. You should not install a new kernel
while the array is degraded, otherwise, even if you do an mdadm --add,
the next reboot will still be degraded! The array is started at boot
time by script. You can see what is in the script of the initrd by
mounting it, e.g.
mount /boot/initrd.img-X.X.X /mnt -o loop
cat /mnt/script
And look for the array start line similar to
mdadm -A /devfs/md/0 -R -u 23d8dd00:bc834589:0dab55b1:7bfcc1ec /dev/hda1 /dev/hdc1
That sounds like what you're seeing
Reply to: