RE: Reclaiming Storage...Re-booting Regularly

"Andy Nolen-Parkhouse"
<aparkhouse=K2GnTyEPumIAvxtiuMwx3w@public.gmane.org> wrote in
000b01c259ad$92ccba20$6501a8c0@ne2.client2.attbi.com:">news:000b01c259ad$92ccba20$6501a8c0@ne2.client2.attbi.com:

> For those installations which have a sizable window of
> availability to perform a more lengthy IPL, do you see any
> downside to permanently changing the IPL attributes?  Some
> people (like me) feel okay about exceeding recommended
> maintenance schedules.
>

Andy, the problem I see with changing the default setting is when
your under emergency conditions, you have to remember to change
things.  Regardless of your 24x7 needs, consider the situation
where all power is lost and your UPS fails and it occurs during
the normal business day.  With the defaults set to always perform
full diagnostics, you'd have that amount of time plus abnormal
IPL time.  Because this doesn't happen often, if ever, you could
forget to make the change via the control panel to use
abbreviated diagnostics.  This in turn could create a huge
problem for you and your business.  The key question in all of
this is "how much longer is *ALL than *MIN?"  Of course, we
really don't know for sure, but I tend to plan for the disaster
and be pleasantly surprised when things work out better.  Or I
don't need the disaster plans at all :)

As far as running full diagnostics more often, I don't see that
as being a problem.

We could explore a couple of options to come up with better
answers.  I'm not sure anyone has benchmarked the difference in
duration since the feature came out in V4R1.  At least the
Performance Capabilities Reference for V5R2 does not have this
comparison.  I'd be willing to collect and publish the
statistics, if there are any willing volunteers on the list.  I
can do some testing, but my test boxes don't come anywhere close
to looking like real "in production" systems.  The data I need is
a copy of your rack configuration (to understand the impact of
towers, IOPs, etc.) and the report produced by running CALL
QWCCRTEC.  The spool files can be emailed to
udcdhy001@sneakemail.com (this is a temporary ID that redirects
to my IBM email ID---it helps to kill SPAM over the long term).

--
Sue
iSeries Advanced Technical Support
Rochester, MN