On 12/6/06, Brian Wipf <brian@clickspace.com> wrote:
> > Hmmm. Something is not right. With a 16 HD RAID 10 based on 10K
> > rpm HDs, you should be seeing higher absolute performance numbers.
> >
> > Find out what HW the Areca guys and Tweakers guys used to test the
> > 1280s.
> > At LW2006, Areca was demonstrating all-in-cache reads and writes of
> > ~1600MBps and ~1300MBps respectively along with RAID 0 Sustained
> > Rates of ~900MBps read, and ~850MBps write.
> >
> > Luke, I know you've managed to get higher IO rates than this with
> > this class of HW. Is there a OS or SW config issue Brian should
> > closely investigate?
>
> I wrote 1280 by a mistake. It's actually a 1260. Sorry about that.
> The IOP341 class of cards weren't available when we ordered the parts
> for the box, so we had to go with the 1260. The box(es) we build next
> month will either have the 1261ML or 1280 depending on whether we go
> 16 or 24 disk.
>
> I noticed Bucky got almost 800 random seeks per second on her 6 disk
> 10000 RPM SAS drive Dell PowerEdge 2950. The random seek performance
> of this box disappointed me the most. Even running 2 concurrent
> bonnies, the random seek performance only increased from 644 seeks/
> sec to 813 seeks/sec. Maybe there is some setting I'm missing? This
> card looked pretty impressive on tweakers.net.
I've been looking a lot at the SAS enclosures lately and am starting
to feel like that's the way to go. Performance is amazing and the
flexibility of choosing low cost SATA or high speed SAS drives is
great. not only that, but more and more SAS is coming out in 2.5"
drives which seems to be a better fit for databases...more spindles.
with a 2.5" drive enclosure they can stuff 10 hot swap drives into a
1u enclosure...that's pretty amazing.
one downside of SAS is most of the HBAs are pci-express only, that can
limit your options unless your server is very new. also you don't
want to skimp on the hba, get the best available, which looks to be
lsi logic at the moment (dell perc5/e is lsi logic controller as is
the intel sas hba)...others?
merlin
