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User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows 98; .NET CLR 1.0.3705)

Description of problem:
The problem occurs on a machine with 512MB RAM and 1024MB swap. top reports 
about 200MB free RAM (not actually free, but used for cache and buffers). Used 
swap space varies between 15MB and 25MB.

iostat (and sar) report that the swap partition is busy (about 15 transaction 
per second).

In my opinion the system shouldn't swap at all while there is enough RAM 
available. Even if one considers that swapping out unused program parts to use 
the freed RAM for harddisk cache might be more efficient there's absolutely no 
justification for this heavy swap activity.

I've disabled swap (via swapoff) to avoid burning out yet another harddisk (one 
rests in peace already due to a similar problem). This resulted in about 20MB 
less free RAM, but the system appears to run fine. I'd prefer a less drastic 
solution, though.

Are there any options in /proc/sys I could use to make swapping out less 
aggressive?

Version-Release number of selected component (if applicable):
kernel-2.4.20-18.9

How reproducible:
Always

Steps to Reproduce:
1. Boot.
2. Wait a few minutes.
3. Watch HD activity light flicker.
    

Actual Results:  Heavy swapping.

Expected Results:  No swapping.

Additional info:

The software running on this system is making heavy use of anonymous mmap().