topic Re: sar -M & top command in Operating System - HP-UX

sar -M & top command

Mariko.N — Wed, 30 Jun 2004 03:26:48 GMT

Hello!

I'd like to know difference between 'top' & 'sar -M' command.

When I execute 'top' & 'sar -M 1 1' simultaneously to check CPU status, the results seem something different.
(top: USER SYS IDLE, sar: %usr %sys %idle)

I'd like to know the reason why.
Thank you.

Mariko

Re: sar -M & top command

Mark Grant — Wed, 30 Jun 2004 03:30:45 GMT

Possibly down to the sampling time of the two tools. If you run "sar -M 1 5", presuming "top" is sampling every five seconds (the default) then I would think the results would be more similar. Remember, the figures are an average over the time period.

Re: sar -M & top command

Simon Hargrave — Wed, 30 Jun 2004 03:36:23 GMT

try sar -M 5 100

top, by default, is taking a sample over 5 seconds, so your sar over 1 second is effectively looking at a smaller set of data. If you sar based on 5 seconds (or run top with -s to set a different sample rate), you'll probably have similar results.

You'll probably only get "very similar" values if you start sam at the same time as top, to ensure they're sampling the same 5 seconds, too.

Re: sar -M & top command

Sanjay Kumar Suri — Wed, 30 Jun 2004 03:39:37 GMT

man top

Set the delay between screen updates to time seconds. The default delay between updates is 5 seconds

If you use following command:

sar -M 5 5

then the output from sar & top may match.

sks

Re: sar -M & top command

Mark Grant — Wed, 30 Jun 2004 03:42:51 GMT

woops, I did get my "sar" arguments the wrong way around didn' I! I keep doing that. Shoud, of course, be "sar -M 5 1" though porbably best to change that "1" for a higher figure for more accurate results.