Re: is my raid1 array really working??

also sprach harland christofferson <debian-user@audubonstrings.com> [2007.09.19.0405 +0100]:
> okay, this is what i have done:
>
> # umount /dev/hdc8
> # mdadm /dev/md4 --fail /dev/hdc8
> # mdadm /dev/md4 --remove /dev/hdc8
> # mdadm /dev/md4 --add /dev/hdc8
>
> cat-ed /proc/mdstat and see that it is resynching ...
> good news.
>
> now, part two of your suggestion ... unmounting
> /dev/hdaX partitions, editing fstab, and remounting.
>
> won't this cause my system to go belly up?

You need to do this from a rescue disk. I recommend grml.

Even though the above procedure *does* restore your RAID and you change /etc/fstab such that on next boot, /dev/mdX would be mounted instead of /dev/hdaX, between the --add and the reboot, something will write to /dev/hdaX and you're back to where you started from.

If you don't have a rescue disk, here's one way which would probably also work, but I can't guarantee it.

  back up the important files
  change /etc/fstab accordingly
  fail and remove /dev/hdcX from all arrays   call mdadm --zero-superblock on all /dev/hdcX partitions   reboot
  readd all /dev/hdcX partitions to the appropriate arrays

-- 
 .''`.   martin f. krafft 
: :'  :  proud Debian developer, author, administrator, and user
`. `'`   
http://people.debian.org/~madduck - 
http://debiansystem.info
  `-  Debian - when you have better things to do than fixing systems
 
"and the sea isn't green
 and i love the queen
 and what exactly is a dream?
 and what exactly is a joke?"
                                                        -- syd barrett

-- To UNSUBSCRIBE, email to debian-user-REQUEST@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org