topic Re: Load calculation in Operating System - HP-UX

Load calculation

Prakash Nair — Tue, 01 Aug 2000 17:27:24 GMT

Is their any formula to calculate the system critcal load?

Re: Load calculation

Antoanetta Naghiu — Tue, 01 Aug 2000 17:33:26 GMT

There are tools available. top command seems to do a very good job. You can try glance (you have to pay for it but available for 60 days as a trial). vmstat (see man vmstat) and others (iostat, netstat, etc, see the other posts in the same issue).

Re: Load calculation

James R. Ferguson — Tue, 01 Aug 2000 17:46:47 GMT

Prakash:

uptime gives the average number of tasks in the run queue over the last 1,5 and 15 minutes. This is a useful "quick" look.

...JRF...

Re: Load calculation

Alan Riggs — Tue, 01 Aug 2000 17:49:45 GMT

All of the above plus sar.

And measurewear/perfView for a historic perspective (non-free)

Re: Load calculation

Brian M. Fisher — Tue, 01 Aug 2000 18:29:09 GMT

sar (system activity reporter) can be setup through cron to capture a large range of performance data i.e. cpu, buffer, block device, tty activity, system calls, swapping, and many other statistics.

To set it up:
1) mkdir /var/adm/sa
2) chown adm:adm /var/adm/sa
3) create the following root cron entry:
0 6-18 * * * su adm -c "/usr/lib/sa/sa1 900 4"
This will run the collection progran every day between 06:00 & 18:00 every 900 seconds (15 minutes"

To view information use:
sar -? -f /var/adm/sa/sa??

where -? is sar option man sar
where sa?? is the date of the month i.e. sa01

Brian
<*(((>< er

Re: Load calculation

Anthony Goonetilleke — Wed, 02 Aug 2000 01:31:02 GMT

Every five seconds, the kernel walks the proc table and counts how many runnable and imminently runnable processes there are at that specific time. The load average is an average of the last 12 totals.

The actual formula is statistical, so the kernel doesn't have to
remember each of the last 12 values. The formula is:

new average = [previous average * e^(-1/12)] + (new value * [1 - e^(-1/12)])

There is a more comprehensive explanation in Document Id W3564348

Re: Load calculation

Vincente Fernandes — Wed, 02 Aug 2000 06:58:33 GMT

Try sar, top, glance(paid product), uptime, w,vmstat etc.