UNIX for Dummies Questions & Answers

Hi All,

I have a pair of sun ultra 5_10 with SunOS 5.5.1.
Both are almost equally patched and set up with simillar applications.

host# uname -a
SunOS host 5.5.1 Generic_103640-24 sun4u sparc SUNW,Ultra-5_10

Even though both have
same amount of RAM ( 512 Mb ) ,
Swap,
and same set of processes running,

they show different values of free memory in "top". They difference is close to 50 Mb.

I had a look at few processes and compared the rss output in ps, they differ!.

Can anyone tell me why is this ?..

Eg:

host1# ps -ef -orss,vsz,comm | grep init
288 448 /etc/init
1136 1880 /usr/openwin/bin/xinit


host2# ps -ef -orss,vsz,comm | grep init
136 448 /etc/init
1120 1880 /usr/openwin/bin/xinit

The host2 is showing 50~60 Mb as free, where as host1 has only 10~15Mb free.


Thanks in advance..

And Ford could probably sell you two "exactly the same" Mustangs and one would be faster than the other - some machines work better than another would be my first point.

Second point - you state "almost equally patched" - so they are different - one of those patches may have made the OS utilize more/less memory, may have been quicker at releasing memory - and you can't tell if they are both in the same 'stage' of processing - maybe the amount of memory being used will be different (the other way around) at another time.

One may have more users conncected to the application that you are not seeing (especially if it's a Oracle/Sybase style app).

Each system is different - boot both at the same time and one may come up faster for no apparent reason.

The question you ask would be impossible to explain a 'reason' with the information provided - you are attempting to find a needle in a haystack.

Does the server with 'the problem' process the work in the time allowed? (if yes - stop worrying)