Re: Can't reboot after power failure (RAID problem?)
On Monday 31 January 2011 10:51:04 email@example.com wrote:
> I posted in a panic and left out a lot of details. I'm using Squeeze, and
> set up the system about a month ago, so there have been some upgrades. I
> wonder if maybe the kernel or Grub was upgraded and I neglected to install
> Grub again, but I would expect it to automatically be reinstalled on at
> least the first disk. If I remove either disk I get the same error
> I did look at /proc/cmdline. It shows the same uuid for the root device
> as in the menu, so that seems to prove it's an MD device that isn't ready
> since my boot and root partitions are each on MD devices. /proc/modules
> does show md_mod.
What about the actual device? Does /dev/md/0 (or /dev/md0, or whatever)
If the module is loaded but the device does not exist, then it's possible
there's a problem with your mdadm.conf file, and the initramfs doesn't
have the array info in it, so it wasn't started.
The easy way out is to boot from a rescue disk, fix the mdadm.conf
file, rebuild the initramfs, and reboot.
The Real Sysadmin way is to start the array by hand from inside
the initramfs. You want "mdadm -A /dev/md0" (or possibly
"mdadm -A -u <your-uuid>") to start it, and once it's up, ctrl-d out
of the initramfs and hope. The part I don't remember is whether or
not this creates the symlinks in /dev/disk that your root-fs-finder
is looking for.
It may be better to boot with "break=premount" to get into the
initramfs in a more controlled state, instead of trying to fix it
in the already-error-ed state, assuming you try the initramfs
thing at all.
And further assuming that the mdadm.conf file is the problem,
which was pretty much guesswork on my part...
Andrew Reid / firstname.lastname@example.org