At 03:17 AM 1/22/98 -0500, Jeff Kell wrote:
>There are tradeoffs.

Unquestionably.  My favorite two words are "It" and "Depends" when it comes
to system performance issues.

>When you are running "flat out desperate" you can
>ill afford a batch monitor like the old Carolian SysPak or Lund's
>background SOS monitor.  But otherwise, they are handy to get some
>overall data as backup to upper management to show you are in trouble.
>I have both products (long story, we're phasing out Syspak), but the
>Syspak product does do weekly/monthly graphs of utilization and other
>pulse points averaged by days and by hour of day.
>
>Of course this is misleading as well, as the values are non-weighted
>averages over a long period of time (5 minutes or more) and those times
>when you have response time in the gutter for 10-15 minutes and 100%
>utilization end up averaged into an hourly graph bar.  Hard to explain
>to the uninformed that 50% utilization over an entire hour is not
>necessarily a good thing (similar to network loading graphs; smoothing
>bandwidth utilization over an entire hour is *no* indicator of LAN
>performance unless you have critical and chronic problems).
>

These are *very* good points Jeff makes.  It is difficult to educate some
users that this is so.  It is also hard to convince some that overall CPU
utilization isn't the whole picture and that you need to look further
before making any assumptions or decisions.  For example, a system which is
100% busy but is running mostly non-critical batch processing is a
completely different kettle of fish than a system running 100% busy the
majority of which is high-priority interactive processing.

>Your mileage may vary.  I prefer the online, on-demand tools, and SOS
>is a good one, particularly the tabular (not graphic) overview, as it
>provides a load average, disc queue lengths, and other important
>information.  But as a disclaimer, I haven't seen Stan's non-MI product
>in action, I'm only comparing Glance/SOS/Sysview.
>

I also prefer SOS :-)  Particularly the tabular screen presentations.

>Jeff Kell <[log in to unmask]>
>
>

Bill