Having worked in a smaller environment for the last 21 years, I can
understand John's reluctance to run a sysplex. If you have one machine, and
it crashes or loses power, then your whole sysplex crashes, and your outage
is probably longer because you have to start 2 Lpars and connect them before
starting your work back up. Granted, if one Lpar crashes, the other will
keep going.
A lot depends on how easy it is for a shop to do IPLs. At P&H Mining, as a
manufacturer, it was very easy. We IPL'd every week. On Saturday at 6:00
P.M., all the CICSs were shut down. It didn't take much more to shut down
batch and IPL, especially since we did backups right after the IPL, and
didn't want anything running anyway. Now that contrasts sharply with my
last job, where they IPL'd once a quarter or even longer.
That brings up a question I had on the part of the post I quoted below. If
you have 2 Lpars in a sysplex, and each Lpar runs say 10 CICSs, how do you
prevent shutting down the 10 CICSs on the system you want to IPL? I know
when I worked at my last job, they had 2 separate z/900s in a sysplex, and
when either one was IPL'd, there was an outage. The bigger machine ran all
the CICSs, and the other ran lots of DB2 batch. They had outages for each
IPL when we were installing z/OS 1.7. Is there a way to migrate the work
from one Lpar to another?
Another comment. I know they could probably get one z/9 box a lot cheaper
than the 2 z/900s, but they really wanted the redundancy of 2 separate
systems. At least it would probably be cheaper considering software costs.
I suspect the z9 is enough more reliable than 2 z/900s and that it would be
worthwhile to make that switch.
Eric Bielefeld
Sr. z/OS Systems Programmer
Milwaukee, Wisconsin
414-475-7434
----- Original Message -----
From: "Skip Robinson" <[EMAIL PROTECTED]>
John,
I don't understand the fervor of your opposition to sysplex. Even on a
single CEC, sysplex offers a degree of increased availability that cannot
be achieved any other way. Even basic sysplex provides benefits, although
I
would strenuously hit up the 'multi-system advocate' for the cost of an
ICF
engine.
SNIP
> The main benefit of a well configured sysplex is that you can bring down
one image for software maintenance while the other one stays up. With a
single CEC, you may still have outages because of hardware changes or
anything requiring POR, but those cases should be much rarer than
scheduled
PTF refreshes.
JO.Skip Robinson
Southern California Edison Company
Electric Dragon Team Paddler
SHARE MVS Program Co-Manager
626-302-7535 Office
323-715-0595 Mobile
[EMAIL PROTECTED]
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO
Search the archives at http://bama.ua.edu/archives/ibm-main.html
