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Re: [SLUG] Adding RAID to Linux *after* installation?
- To: slug@xxxxxxxxxxx
- Subject: Re: [SLUG] Adding RAID to Linux *after* installation?
- From: Jeff Waugh <jdub@xxxxxxxxxxxxxx>
- Date: Sun, 30 Jul 2006 07:03:37 -0700
- User-agent: Mutt/1.5.12-2006-07-14
> mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/hda7 /dev/sda7
> it refuses, as /dev/hda7 ("/") is mounted.
Okay, so do this instead:
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda7 missing
That will create a 2 device array with one missing device. You need to bring
up the array (watch /proc/mdstat to see its status), mount it, then copy
over everything from / (using cp -a or similar). Now set up everything in
the copied partition to boot from /dev/md0 instead of /dev/hda7, and then
reboot. Boot from /dev/hda0 by using the grub menus (if you've made sure
they're changed), or edit the boot command line to do it manually. You
should find yourself running a system with / on /dev/md0. At this point, you
can use mdadm to add /dev/sda7 to the array - after checking everything is
okay, of course! :-)
This is not a wildly uncommon thing to do, but it's so easy to install with
RAID now that I think most people just do that.
> Obviously I should try this on the /home partition, not slash, until I get
> the steps worked out. At least that way if I lose any data, it'll be a
> tiny amount of junk instead of 10GB of carefully setup Linux system!
That's a good idea. :-) Running an array reliably on / or /boot requires
some extra work anyway.
linux.conf.au 2007: Sydney, Australia http://lca2007.linux.org.au/
I don't know whose brain child it was, but it was quite an ugly child.