Christofer C. Bell wrote:
On 12/15/05, Robin Laing <Robin.Laing@xxxxxxxxxxxxxxx> wrote:
> Accepted practise is to run mirrors across controllers for reasons of
performance (ie; avoding the situation you're seeing) and for fault
tolerance (loss of a controller). If you have a correctly configured
/etc/mdadm.conf file, then you should (in theory) be able to simply
plug the drive into the other controller and have it work.
The md subsystem does not look at, for lack of a better term, the
"hardware path" of the drives it's assembling into an arry, it looks
at the UUID that's tagged to each disk. This UUID is unique per RAID
volume regardless of where the disks are physically located in your
machine.
You can see this UUID by running the following command:
# mdadm --detail --scan | grep ARRAY
In fact, you can put the output of that command in /etc/mdadm.conf and
have a more or less working configuration. You may choose to add
"auto=md" at the end each line to force the md software to create the
relavent md entries in /dev at boot time should they be found to not
exist.
You'll also need to add the following two lines on top of each ARRAY entry:
DEVICE partitions
MAILADDR root
The first line tells mdadm to use /proc/partitions when determining
what it should scan for md plexes. You can specifically enumerate
partitions or devices here instead as outlined in the manpage for
mdadm.conf. The second line tells mdadm who to email should a plex in
an md device fail or otherwise experience problems.
Best of luck!
--
Chris
Chris,
Thank you for the information. I will give it a try and see what
happens. md and lvm are both new to me. I wish I had thought of this
when I added the drives.
If it is that easy, I will be a very happy boy. :) But as we all
know, there is something that will make that 5 minute job a 3 hour task.
Robin
