Subject: Re: RAIDFrame One or Many
To: Caffeinate The World <mochaexpress@yahoo.com>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: netbsd-users
Date: 04/15/2003 22:58:36
On Mon, Apr 14, 2003 at 02:09:39PM -0700, Caffeinate The World wrote:
> I have two disks sd0 and sd1. I want to make a RAID1 from both for /,
> swap, /usr, and /var:
> 
> Partition     Mount
> a             /
> b             swap
> d             /var
> e             /usr
> 
> Would it be more efficient to make one huge partition of type RAID on
> sd0 and sd1, then make raid0a, raid0b, raid0d, raid0e or make 4
> different RAIDs: raid0a, raid1a, raid2a, raid3a with each having a
> partition like above from sd0 and sd1?

Probably better with only one raid, as RAIDFrame has some I/O scheduling
knowledge, which are of little use when there are different raid volumes
on the same physical disks.
However, because of a problem with swap on raidframe, I would make one raid
for a+b and a second for everything else (this is how I setup my sustems
these days). The problem is that the swap partition isn't closed on
halt/reboot, so the raid is dirty on next boot and it rebuilds parity.
Using a separate, smaller raid for swap will make the parity rebuild
short enouth to not be too annoying.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 24 ans d'experience feront toujours la difference
--