Re: MDADM Software Raid Woes

From: Nick Andrew
Date: Thu Dec 18 2008 - 01:56:21 EST


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.
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