On Thu, 6 Feb 2003, eric soroos wrote:
> > I found that the write performance for large writes on an Escalade
> > 7850 was great, but I couldn't coax more than about 120 writes
> > per second out of the thing in any configuration (even writing to
> > separate disks in JBOD mode), which made it very disappointing for
> > database use. (The individual disks on the controller, modern IBM 60
> > GB IDEs, could do about 90 writes per second.)
> ...
> Peaks for striped are @ 80, peaks for single are ~ 100, peaks for
> mirror are around 100. I'm curious if hw mirroring would help, as I am
> about a 4 disk raid 5. But I'm not likely to have the proper drives
> for that in time to do the testing, and I like the ablity to break the
> mirror for a backup. For comparison, that same system was doing 20-50
> without the extra 512 stick of ram and on the internal single drive.
Hm. That's still very low (about the same as a single modern IDE drive).
I'm looking for an IDE RAID controller that would get me up into the
300-500 reads/writes per second range, for 8K blocks. This should not
be a problem when doing striping across eight disks that are each
individually capable of about 90 random 8K reads/writes per second.
(Depending on the size of the data area you're testing on, of course.)
See http://randread.sourceforge.net for some tools to help measure this.
cjs
--
Curt Sampson <cjs@cynic.net> +81 90 7737 2974 http://www.netbsd.org
Don't you know, in this new Dark Age, we're all light. --XTC
