[ILUG] swap

[Niall O Broin]

On 29 Apr 2005, at 13:54, Pat wrote:

>>> searching i noticed that both "free" & xosview show that it's not
>>> using any
>>> swap memory. I'm running SuSE 9.2 & set up a swap of 1Gb using YAST &
>>> later
>>> had a go at setting it up at the command line with "makeswap -c"
>>> followed by "swapon /dev/hda1" but no joy. I have been doing a little
>>> tweeking lately using YAST but cant think what i could do to stop it
>>> using
>>> swap memory. Any ideas or suggestions would be very welcome.
>>
>> What happens when you do   swapon /dev/hda1   ?
>>
>>
>> Niall
>  Well the machine didn't complain when i did swapon /dev/hda1, so i 
> assumed
> all was ok & the swap partition showed up when i ran the free command, 
> but no
> swap is being used

Swap is only used when it's needed. If you have a swap partition made, 
and in use, and free shows it, it will be used if needed. If you want 
to see your swap being used, save this

#include <stdlib.h>

int main()

{
   int megs = 512;
   free(calloc(megs, 1048576));
   exit(0);
}

as, say, gobble.c and compile it with   cc -o gobble gobble.c

changing the value of megs to change how many megabytes it allocates 
and then do

free; ./gobble; free

and you should see some swap usage, unless you have gobs of memory, in 
which case, increase megs.


Niall