5.5.6. Reserved Pool Capacity (RPC)
Another feature of shared processor pools is the option to reserve additional processor shares. This reserved pool capacity can be configured using the reserved_pool_proc_units attribute with the “ms chprocpool” command:
$ ms chprocpool ms11 testpool reserved_pool_proc_units=0.4
These additional processor shares are guaranteed to be available to the LPARs in a shared processor pool in addition to their guaranteed entitlement. The shares are divided according to the weights of the LPARs within the shared processor pool.