Memory Issue

[Kevin Buettner]

On Dec 13,  8:54am, Sonja Michelle L. Thomas wrote:

> I have 256MB of RAM in my system running RH6.2 on a PII 233Mhz MMX.
> here is what free is reporting:
> 
>               total       used       free     shared    buffers    
> cached
> Mem:        257720     218468      39252      52564     138004     
> 34356
> - -/+ buffers/cache:      46108     211612
> Swap:       130748       4448     126300 
> 
> Now it seems to bounce back and forth between low usage, like 40-60MB
> used to 200+ used. It' almost like windows in this issue:
> I attached a ps -A to a txt file (was to spammy to paste). I am
> running KDE ver 1.1.2 and even with that, of course being displayed
> on an Xserver on another machine, I still get really good memory
> useage cept when I get this moments when it's all taken up. I'm
> stumped.

Which number in the above ``free'' report are you looking at?  If
you're looking at the "Mem:" line, this line reports the amount of
memory used by both applications and the (file) buffer cache.  The
line you should be looking at to determine how much memory is being
used by your applications is the second line: "-/+ buffers/cache".
In your free report, above, you have only 45MB being used by your
applications, with 206MB free.

If you're looking at the top line for your free numbers, you'll
see this bounce around quite a bit.  If you start a short-lived,
memory hungry application, it'll "steal" some memory from the
buffer/cached pool and then release it when it is done.  The
kernel won't immediately reuse it for file caching, so you'll
have some truly free memory for a while.

I don't think that there is any cause for concern on your part.  The
Linux kernel is merely attempting to make the most of the resources
that you have on your machine.  In fact, throwing more memory in the
machine is almost always beneficial even if you do not expect your
applications to directly use it.  The reason is that the kernel can
use it for caching files (think of it as a smart RAM disk w/ backing
store) which will both improve performance as well as limit wear and
tear on your hard drives.

Kevin