[plug] re; Swap size

[John Summerfield]

> Think I remember reading in the paperwork that you should leave about 100-120
>  Mb for swap,
> and then enable growable in the setup..
> 
> Will stand the correction if I'm wrong...

There is absolutely no point in 100 Mb swap if you only have 8 Mb RAM - 
you simply do no have enough RAM to support a matching working set.

My system has 64 Mb RAM, 128 Mb swap. It's just been thrashing - less went 
beserk. Here's part of what "top" said:

  8:00am  up 11:58,  7 users,  load average: 1.43, 1.90, 1.45
90 processes: 87 sleeping, 1 running, 2 zombie, 0 stopped
CPU states:  1.6% user,  2.5% system,  0.0% nice, 95.7% idle
Mem:   63132K av,  62572K used,    560K free,  29332K shrd,   1308K buff
Swap: 128484K av,  90956K used,  37528K free                 52820K cached

  PID USER     PRI  NI  SIZE  RSS SHARE STAT  LIB %CPU %MEM   TIME COMMAND
 2529 summer    18   0   532  476   336 R       0  2.5  0.7   0:04 top
 1818 root       7   0  9568 3032   780 D       0  0.8  4.8   3:48 X
 2524 summer    10   0 52284  25M 26388 D       0  0.6 41.7   8:50 less
 2531 root      16   0   484  472   416 D       0  0.3  0.7   0:00 crond


First: I was using almost all of RAM.
Second: I was using about 90 Mb swap.
Third: "less" has 25 Mb. Observations over a few minutes showed it varying 
wildly from 0 to 41 Mb.

I doubt that there's much use to me in having more than about 90 Mb swap: 
it may be that a different workload would use more without thashing.

If the performance I sufferent a while ago occurred regularly, I'd be off 
to my computer shop for another DIMM.


btw It IS possible to use swap files rather than (or as well as) swap 
partitions: this is more flexible as one doesn't have to repartition 
drives to adjust the amount of swap space.


-- 
Cheers
John Summerfield
http://os2.ami.com.au/os2/ for OS/2 support.
Configuration, networking, combined IBM ftpsites index.