Originally posted by: ren.hoek

I've been tasked to migrate a 2-way p630@1.45GHz into an LPAR in a 4-way p5-570@ 1.9GHz server.

Question is how do I calculate the LPAR's processing requirements: min, desired, maximum so that I have a simillar or better processing power like the p630?

Does the speed(GHz)has any influence on the requirements, how so? Is there a formula we can use to get an estimate for the min, des, and max?

I understand the minimum pu is at least 0.1. Based on the above physical processors, what would be an appropriate number for the desired and maximum? And how is that calculated?

Sorry for the too many questions. I'm going to have an official training on LPAR next month but it's not soon enough to help me understand this.

Any suggestion or help is much appreciated.

Thanks!
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Originally posted by: SystemAdmin

Your sales rep that sold you the 570 should have calculated the rperfs for you. I think the rperf sheets are available online someplace, forget where off the top of my head.
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Originally posted by: j.gann

suggested reading: redbook sg247940 (google)

quick brushup:
lpar won't start if theres less than "min" available, will try to grab "des" on startup, and will be able to grow to "max" by means of DLPAR.

the nice thing about virtualization is that you can start your lpar with a best guess and then monitor ressource usage and adjust ressources in-flight they fit the workload.
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Originally posted by: EricGapinski

According to the facts and features doc (you might have to search a bit to find an older one) a 2-way p630@1.45GHz has an rperf value of 6.07. A 4-way p5-570@ 1.9GHz has an rperf of 22.26. If you only had 2 of the processors active you'd have an rperf of 11.16. While the math isn't exact you would probably fall fairly close performance wise (rperf wise) with an LPAR set at 1.1 processors on the 570. Of course the nature of your application might alter where you want to be, for instance if you have a need for several concurent threads, even though you'd have a higher rperf, you might still need the 2 CPU's in the LPAR.

For min, des, max values, I like to set min no less then half my desired, my des based on the rperf target I'm trying to hit, and my max all the CPU's in the frame. This gives me lots of room to DLPAR CPU's around between partitions as needed.

For the min value, depending upon the number of virtual processors you assign, it changes what you can set for the min. If you have a min 2 virtual processors, then your min can't be lower then .2. These values mostly just effect what your able to change dynamically, though be carefull if you overallocate CPU to multiple LPARS at the desired level (say all the LPARS desired CPU totals 5 on your 4-way) as boots of partitions will get less then desired CPU in those situations.
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Originally posted by: ren.hoek

Thanks Eric. That helps and it's a good place for me to start!

ren
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Originally posted by: Frankie.Ferrer

Thanks for your explanation! It helps me out of the problem, It's very valuable.
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