Re: tuning questions

On Thu, 2003-12-04 at 12:27, Richard Huxton wrote:
> On Thursday 04 December 2003 19:50, Jack Coates wrote:
> >
> > I'm trying to set Postgres's shared memory usage in a fashion that
> > allows it to return requested results quickly. Unfortunately, none of
> > these changes allow PG to use more than a little under 300M RAM.
> > vacuumdb --analyze is now taking an inordinate amount of time as well
> > (40 minutes and counting), so that change needs to be rolled back.
>
> You don't want PG to use all your RAM, it's designed to let the underlying OS
> do a lot of caching for it. Probably worth having a look at vmstat/iostat and
> see if it's saturating on I/O.

latest changes:
shared_buffers = 35642
max_fsm_relations = 1000
max_fsm_pages = 10000
wal_buffers = 64
sort_mem = 32768
vacuum_mem = 32768
effective_cache_size = 10000

/proc/sys/kernel/shmmax = 500000000

IO is active, but hardly saturated. CPU load is hefty though, load
average is at 4 now.

procs memory swap io
system cpu
r b w swpd free buff cache si so bi bo in cs us
sy id
0 2 1 2808 11436 39616 1902988 0 0 240 896 765 469
2 11 87
0 2 1 2808 11432 39616 1902988 0 0 244 848 768 540
4 3 93
0 2 1 2808 11432 39616 1902984 0 0 204 876 788 507
3 4 93
0 2 1 2808 11432 39616 1902984 0 0 360 416 715 495
4 1 96
0 2 1 2808 11432 39616 1902984 0 0 376 328 689 441
2 1 97
0 2 0 2808 11428 39616 1902976 0 0 464 360 705 479
2 1 97
0 2 1 2808 11428 39616 1902976 0 0 432 380 718 547
3 1 97
0 2 1 2808 11428 39616 1902972 0 0 440 372 742 512
1 3 96
0 2 1 2808 11428 39616 1902972 0 0 416 364 711 504
3 1 96
0 2 1 2808 11424 39616 1902972 0 0 456 492 743 592
2 1 97
0 2 1 2808 11424 39616 1902972 0 0 440 352 707 494
2 1 97
0 2 1 2808 11424 39616 1902972 0 0 456 360 709 494
2 2 97
0 2 1 2808 11436 39616 1902968 0 0 536 516 807 708
3 2 94

--
Jack Coates, Lyris Technologies Applications Engineer
510-549-4350 x148, jack(at)lyris(dot)com
"Interoperability is the keyword, uniformity is a dead end."
--Olivier Fourdan