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IBM LPAR Processor Issue (EC vs vCPU)

I have an LPAR and processor settings are as follows..

Available system processing units: 9.8
Available system processing units
(with releasable amount from other partitions): 9.8

Minimum Processing units : 0.1
Minimum Virtual Processors units : 1

Assigned Processing units : 1.4
Assigned Virtual Processors units : 4

Currently My CPU is pegged and on my TOPAS, I see that the ec% is 1400+ and CPU is 200% and I want to add more resources.

So here is my question :

1. Does it make sense to add more virtual processing units like increase 4 to like 8

Or

2. Does it make sense to increase the Assigned Processing Units from 1.4 to 4

So please suggest....
0
Ramu Shetty
Asked:
Ramu Shetty
1 Solution
 
woolmilkporcCommented:
Increasing the number of VPs will not make sense, because this won't add any processing power to the LPAR (the available power will just be distributed differently).
Increasing the Entitled Capacity will actually add processing power to the LPAR, so this should be the way to go.

Please keep in mind that you must configure at least one VP per real processing unit, because one VP can be mapped to one real PU at max. So lack of VPs will lead to PUs idleing around.
Given this rule you'll further have to decide if your LPAR has to serve few, CPU-hungry threads or many, not so hungry ones. The more threads, the more VPs (up to one VP per 0.1 PU resp. one VP per 0.05 PU on Power7+).

Here is a nice article on all this:
http://www.ibmsystemsmag.com/aix/administrator/lpar/vp_entitlements/
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