Determining physical memory usage

[Jay A. Konigsberg]

In article <3634 at umbc3.UMBC.EDU> rostamia at umbc3.umbc.edu (Rouben Rostamian) writes:
>Is there a utility to determine what fraction of the physical memory 
>is being used on a machine?
>
>The closest I can come to is to execute the ps command (with
>optional flags) to get the percentage of memory used by individual
>processes, then add up all the percentages.  [I am not even sure
>if the memory referred by ps is virtual or physical memory.]
>
>I have a DECstation 3100 with 8MB of memory.  The reason I want to check
>the memory usage is to determine whether the memory gets saturated at all,
>and whether investing in additional memory modules is worthwhile. 
>
Well, I saw your first post and wondered if someone would answer - guess
not. So, here is my shot.

** from the "Unix System V/386" manual **

ps -el will produce most of the desiered information you need with one
known cavate. Different users running the same program will report the
same memory for that program being used twice when its only being used
once. One copy is in memory and multiple file/program pointers and data
areas will be maintained.

The collum for SZ is the info your after.

Also, at boot time the system will report the amount of memory used by
the kernel (on a 3B2 anyway), try checking the output of the "prtconf"
and "sysdef" commands (3B2's also).

If this information isn't easily available, you will have to go into
the kernel configuration file (or the sysdef output) and figure it all
up from the information in the Systems Administrators reference manual.

-- 
-------------------------------------------------------------
Jay @ SAC-UNIX, Sacramento, Ca.   UUCP=...pacbell!sactoh0!jak
If something is worth doing, its worth doing correctly.