5.1.1. Adding Dedicated Processors

If a dedicated LPAR has an active RMC connection to the HMCs, dedicated processors can be added (and of course removed) during operation. Two conditions must be met for this:

    1. The current number of dedicated processors must be less than the maximum permitted number of dedicated processors for the LPAR.
    2. The desired number of processors must also still be available.

How many dedicated processors are currently assigned to an LPAR and how many are possible can easily be determined using “lpar lsproc“:

$ lpar lsproc aix02
            PROC        PROCS           PROC_UNITS                         UNCAP   PROC
aix02  ded   1    2        4    -    -        -    keep_idle_procs    -       -

The LPAR aix02 currently has 2 dedicated processors and can be expanded to up to 4 dedicated processors. The number of processors can of course also be determined from the LPAR operating system:

aix02 # lsdev -l proc*
proc0 Available 00-00 Processor
proc8 Available 00-08 Processor
aix02 #

There are currently 10.15 processors available on the underlying managed system (ms06):

$ ms lsproc ms06
ms06  20.0       20.0          10.15  64

This means that 1 or 2 dedicated processors can be added to the LPAR aix02 without any problems. The command for this is “lpar addprocs” (add processors):

$ lpar addprocs aix02 1

In the example, one dedicated processor was added. The processor is immediately available to the operating system; no further configuration is necessary on the AIX LPAR:

aix02 # lsdev -l proc*
proc0  Available 00-00 Processor
proc8  Available 00-08 Processor
proc16 Available 00-16 Processor
aix02 #

If an LPAR is powered off or has no active RMC connection to the HMCs, the number of dedicated processors can only be changed in the profile of the LPAR:

$ lpar -p standard addprocs aix02 1

However, the change only takes effect when the LPAR is reactivated (specifying the changed profile).