Re: MDADM Software Raid Woes

[Nick Andrew <nick@nick-andrew.net>]

On Wed, Dec 17, 2008 at 11:33:31PM -0500, Dylan Taft wrote:
> I created the raids with the mdadm tool, originally configured manually
> /dev/md0 for sdb1/sdc1 raid1 to be mounted as /boot
> /dev/md1 for sdb2/sdc2 raid0
> 
> I created 3 partitions on md1, one for future /, one for swap, one for
> future /home.
> So I had /dev/md0, md1, and /dev/md1p1,/dev/md1p2/dev/md1p3

Why not use LVM for /dev/md1 ?

	pvcreate /dev/md1
	vgcreate myvg /dev/md1
	lvcreate -L 10G -n root myvg
	lvcreate -L 2G -n swap myvg
	lvcreate -L 20G -n home myvg

Also since you have specified raid0 for /dev/md1 you could
use striping under LVM instead of RAID:

	pvcreate /dev/sdb2 /dev/sdc2
	vgcreate myvg /dev/sdb2 /dev/sdc2
	lvcreate -L 10G -n root -i 2 -I 32 myvg
	lvcreate -L 2G -n swap -i 2 -I 32 myvg
	lvcreate -L 20G -n home -i 2 -I 32 myvg

That way you have some flexibility in your use of sdb2
and sdc2, e.g. you can move your LVs off sdc2 if you want
to replace or extend it later.

Nick.