Subject: Re: using different RAID types on the same disk array
To: Geert Hendrickx <ghen@NetBSD.org>
From: Greg Oster <oster@cs.usask.ca>
List: netbsd-users
Date: 12/20/2006 13:35:30
Geert Hendrickx writes:
> Hi,
>
> looking for some advice on RAIDframe here;
>
> On a machine with two SATA disks, is it a good idea to create
> RAID-1 (mirror) and RAID-0 (stripe) arrays on the same set of
> disks? I'd like to have the benefits of RAID-1 for my system
> and data partitions and RAID-0 for all recoverable data like
> /tmp, cvs trees, obj and work dirs, ...
I'd put /tmp on RAID-1 too :)
> How will the interference between the two raid arrays impact
> performance? For example when reading from both parts at the
> same time, will the RAID-1 automatically read from a disk not
> being accessed by the RAID-0, or not?
RAIDframe won't make that distinction... But if you're reading
any sort of big files from the RAID-0 you're going to be using both
disks anyway, and it won't matter which disk the RAID-1 picks for
a particular IO.
> Or should I use the drives independantly?
My gut reaction is that with RAID-1 and RAID-0 you won't notice any
performance issues in day-to-day use... So just pick the setup
appropriate for safeguarding your data and run with that...
Later...
Greg Oster