Memory usage is always high

[Kapil Jha]

Hi All
I am using DS15 server
Compaq Tru64 5.1
Physical Memory 512MB
Swap 4096MB

although memory is quite less but it always shows near 90%.I thinks there can be a memory leak so any one can tell me how to confirm if there is any memory leak or some other problem.
Thanks

[Steven Schweda]

What "shows near 90%"?

A memory leak normally appears as a process
whose virtual memory size keeps increasing.

Unused memory is a waste of good silicon.

[Ivan Ferreira]

Run vmstat, if the system is not paging, your memory usage should not be a problem.

[Hein van den Heuvel]

I do not think the high memory usage alone signifies a problem.
Only when combined with increasing swap usage would I be concerned about memory leaks. In that case a vmstat report woudl also showongoing, undesirable, pin and pout rates.

Tru64 may simply be trying to optimally use the memory, notably for the UBC cache.
The maximum for this is controlled through a dynamic sysgen param max_ubcpercent and default setting for this system param is to allow it to use 100% of the memory. So the system may well be workgin as intended.
To check the settings for yoru system try:

sysconfig -q vm | grep ubc

These days 512 MB is a modest amount of memory, so it feels ok for me to see teh ubc cache to max out on your system.

For further info check the man pages, or google: +tru64 +ubc_maxpercent


This will lead to for example:

http://www.phys.uu.nl/DU/Tru64_5.0/HTML/ARH9GATE/CHVMXXXX.HTM


hth,
Hein.

[Kapil Jha]

Closing thread....