On Wed, May 07, 2008 at 04:27:43PM -0400, George Georgalis wrote:
On Wed 07 May 2008 at 11:41:55 AM -0700, Brian Buhrow wrote:
Hello. My suggestion is to check the performance, if possible, of a
hardware raid card versus raidframe in a given eenvironment. The reason is
that I've run into a number of situations where raidframe out performs
hardware raid cards by a good margin, and this was somewhat of a surprise
until I started asking around, and found that, in fact, my experience
wasn't that unique. In fact, I think if you google around for hardware
raid versus software raid, you'll find quite a few people hav had the
experience that I have.
this sounds rather contrary to what I'm familiar with... especially
since this is a high end raid card. can you provide any references?
a google does not confirm your assertion.
My ARC-1130 is much faster than any raidframe I have ever used (even in
RAID6 mode).
Under xen dom0:
# time dd if=/dev/zero of=foo bs=1m count=10000
10000+0 records in
10000+0 records out
10485760000 bytes transferred in 61.904 secs (169387438 bytes/sec)
0.029u 33.433s 1:01.92 54.0% 0+0k 127+325io 1pf+0w
# time dd of=/dev/zero if=foo bs=1m count=10000
10000+0 records in
10000+0 records out
10485760000 bytes transferred in 39.992 secs (262196439 bytes/sec)
0.030u 19.542s 0:39.99 48.9% 0+0k 0+0io 0pf+0w
domU, a different partition:
# time dd if=/dev/zero of=foo bs=1m count=10000
10000+0 records in
10000+0 records out
10485760000 bytes transferred in 68.653 secs (152735641 bytes/sec)
0.000u 39.113s 1:08.65 56.9% 0+0k 0+173io 0pf+0w
# time dd of=/dev/zero if=foo bs=1m count=10000
10000+0 records in
10000+0 records out
10485760000 bytes transferred in 34.276 secs (305921344 bytes/sec)
0.049u 21.457s 0:34.27 62.7% 0+0k 0+1io 0pf+0w
This system is not completely idle which may affect the results
(running several domU's with web and sql servers, innd, etc.).