Re: Need to find out which process is hitting hda

Ow Mun Heng <Ow(dot)Mun(dot)Heng(at)wdc(dot)com> writes:
>> vmstat would confirm or disprove that particular guess, since it tracks
>> swap I/O separately.

> procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
> r b swpd free buff cache si so bi bo in cs us sy id wa st
> 2 6 300132 5684 4324 315888 420 32 1024 644 1309 485 35 11 0 54 0
> 0 6 299820 6768 4328 313004 588 76 3048 576 1263 588 36 12 0 52 0
> 0 6 299428 5424 4340 313700 480 36 2376 104 1291 438 24 9 0 67 0
> 2 6 298836 5108 4268 313788 800 0 2312 216 1428 625 30 10 0 60 0
> 2 6 298316 5692 4192 313044 876 0 1652 1608 1488 656 33 11 0 56 0
> 2 6 298004 6256 4140 312184 560 4 1740 1572 1445 601 42 11 0 47 0

> I kept looking at the io columns and didn't even think of the swap
> partition. It's true that it's moving quite erratically but I won't say
> that it's really thrashing.

Hmmm ... my experience is that the si/so columns should show *zero* under
normal load. What you're showing here is swap as a sizable percentage
of total I/O load, and with the CPU spending the majority of its time
in I/O wait, that's clearly where you need to focus your attention.

> (YEP, I know I'm RAM starved on this machine)

Yeah, that's what it looks like. Head down to your local CompUSA and
get some RAM at fire-sale prices ...

regards, tom lane