Re: disk performance benchmarks

On Tue, 2004-09-14 at 14:45, Jim C. Nasby wrote:
> On Tue, Sep 14, 2004 at 11:11:38AM -0700, Jeffrey W. Baker wrote:
> > procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
> > r b swpd free buff cache si so bi bo in cs us sy id wa
> > 3 0 216 13852 39656 7739724 0 0 820 2664 2868 2557 16 2 74 7
> > 0 0 216 17580 39656 7736460 0 0 3024 4700 3458 4313 42 6 52 0
> > 0 0 216 16428 39676 7737324 0 0 840 4248 3930 4516 0 4 89 8
> > 0 1 216 18620 39672 7736920 0 0 7576 516 2738 3347 1 4 55 39
> > 0 0 216 14972 39672 7738960 0 0 1992 2532 2509 2288 2 3 93 3
> > 0 0 216 13564 39672 7740592 0 0 1640 2656 2581 2066 1 3 97 0
> > 0 0 216 12028 39672 7742292 0 0 1688 3576 2072 1626 1 2 96 0
> > 0 0 216 18364 39680 7736164 0 0 1804 3372 1836 1379 1 4 96 0
> > 0 0 216 16828 39684 7737588 0 0 1432 2756 2256 1720 1 3 94 2
> > 0 0 216 15452 39684 7738812 0 0 1188 2184 2384 1830 1 2 97 0
> > 0 1 216 15388 39684 7740104 0 0 1336 2628 2490 1974 2 3 94 2
> > 6 0 216 15424 39684 7740240 0 0 104 3472 2757 1940 3 2 92 2
> > 0 0 216 14784 39700 7741856 0 0 1668 3320 2718 2332 0 3 97 0
> >
> > You can see there's not much progress being made there. In the
>
> Those IO numbers look pretty high for nothing going on. Are you sure
> you're not IO bound?

Just for the list to get an idea of the kinds of performance problems
I'm trying to eliminate, check out these vmstat captures:

http://saturn5.com/~jwb/pg.html

Performance is okay-ish for about three minutes at a stretch and then
extremely bad during the fourth minute, and the cycle repeats all day.
During the bad periods everything involving the database just blocks.

-jwb