On Wed, Mar 08, 2000 at 09:14:02PM +0100, Holger Kiehl wrote:
>
> Why don't you try SW raid?
>
The Mylex controllers I have don't do SCSI, it presents a block
device. I think I'm going to try these drives on my NCR controller
just to get a base-line on what kind of write performance they are
capable of. Maybe I'll try software RAID when I do that. What sort
of CPU usage does software RAID use? Also, does it work on the Alpha
platform? Last time I tried to get it working (granted I didn't spend
a lot of time on it), I was unable to get very far.
In the end, I don't think software RAID is an option for HPC. It is
likely in a production system we will want to have a great deal of
space on each I/O server with many RAID chains on each of them. I
don't think I would see the best performance using software RAID. To
add to the complexity, I'll be doing striping across nodes for our
cluster file system. Probably what will happen is I'll use Fibre
Channel with an external RAID "smart enclosure". This will allow for
more storage and more performance per I/O node than what I could
achieve by using host RAID adapters.
BAPper
