I checked out an MVS Image profile on my (brand spanking new!) z196. It 
looks the choice is between dedicated or shared CPs. A CF LPAR offers more 
choices, but oddly fewer choices than the z10 it replaced. 

.
.
JO.Skip Robinson
SCE Infrastructure Technology Services
Electric Dragon Team Paddler 
SHARE MVS Program Co-Manager
626-302-7535 Office
323-715-0595 Mobile
jo.skip.robin...@sce.com



From:   Barbara Nitz <nitz-...@gmx.net>
To:     IBM-MAIN@bama.ua.edu
Date:   02/15/2012 08:58 PM
Subject:        Re: Dedicated vs. Shared CPs
Sent by:        IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu>



>Is it possible to mix shared and dedicated CPs on the same LPAR?
No. Not on a z9 and not the way you mean.

The RMF report deals with what an lpar can look like when it uses 
Hiperdispatch. That is not available on a z9.
Hiperdispatch semi-dedicates logical processors to physical processors 
depending on the workload. And most probably depending on the number of 
physical cps. (Which is why we asked for the number of your physical cps 
in the other thread - you haven't answered that!)  Once hiperdispatch is 
on, a physical cp gets a weight, which can be low, medium or high. High 
amounts to being (semi-)dedicated.

>Does anyone run mixed like this, a dedicated number to cover the minimum 
expected MSU of an LPAR, then some logicals to float between LPARS?
Everyone who uses hiperdipatch.

>Does anyone know what is needed in terms of outages/lpar resets to move 
from a completely logical CP environment to a mixed environment?
An upgrade to a machine supporting hiperdispatch. Which means at least one 
IPL. But as you can see from my questions starting this thread, it is 
possible that you cannot use hiperdispatch - whenever your logical to 
physical cp ratio is so bad that 4 or more logical cps compete for one 
physical, due to the number of lpars you have, for instance. In the very 
first presentation I heard (by Bob Rogers) about hiperdispatch, he said 
that it will turn itself off if the ratio is really bad. I haven't heard 
that confirmed anywhere, though.

And coming from a z9 presumably to a z196, chances are very good that you 
would loose physical cps to keep money down. Try making your bosses 
understand that they cannot use the same number of logicals when the 
number of physicals decreases....

Barbara Nitz


----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN

Reply via email to