Hi Glenn,
> > is performance. We have yet to get s/w RAID to perform any faster than
> > 25MB/s (according to Bonnie) in any configuration or RAID level.
> 25MB/s ?
> Ive personally gotten 37MB/s with 3 quantum ide drives in raid0 mode,
> each drive on its own channel.
Maybe he is rather talking about RAID5 (and maybe SCSI). I also was a bit
surprised as throughput seems to be limited to 25MB/s on my system (I already
posted a mail on this topic some months ago).
I had tried 4 * IBM DDRS 9GB on 2 UW SCSI channels: 25MB/s RAID5 (dual
celeron 500 system, bonnie block read and write).
I also had tried / am trying 4 * IBM DNES 9GB UW on 2 UW channels: this also
gives 25MB/s, same system (read and write).
The strange thing: measured individually, these DNES HDDs give about 50% more
throughput than DDRS (bonnie), but RAID5 throughput doesn�t change
significantly.
I�m still trying to get why this is like that. Looking at the 2 UW channels
with 2 * 40MB/s and at a single drive rate of about 15-18MB/s, there should be
more throughput possible.
> I think you should be able to get better than 25MB/s without too much
> problem.
I�m using an AIC7895 dual UW SCSI controller, 2 drives on each channel.
What could I do more to optimize throughput ?
Thomas
