All of the terms minimum, desired, maximum, guaranteed and entitled capacity apply to processing units assigned to LPARs. This is only applicable to micro-partitioning. I am going to explain these terms one by one as below:
The minimum number of processing units which have to be assigned to the partition is called minimum capacity. This capacity is the committed value for the particular partition. Without this much of processing units partition can not start. This capacity can not be used to start another shared partition.
Desired capacity is the optimum number of processing units we desire for an application to work efficiently. An LPAR is started with this value as the preferred value, but this may not always be possible. For example, if not enough resources are available in shared processor pool, then value greater than or equal to the minimum value will be used to start the partition instead of desired value.
This is the value we generally use during DLPAR. The purpose is to set the upper limit of moving the resources to other LPAR.
Guaranteed value is between minimum and maximum. Guaranteed value becomes important when we talk about capped and uncapped mode of processor sharing. Its normally equal to the desired value but not always. Sometimes it may be greater or less than desired value.
In capped mode the processing units given to a partition can not exceed guaranteed value, even though resources may be available in shared processing pool.
In uncapped mode the guaranteed value can be exceeded as per requirement.
So, order can be setup something like:
Minimum < Guaranteed < Desired < Maximum
This term comes into picture only once the partition is activated. In capped mode itâ€™s equal to that of guaranteed value. In uncapped mode it depends upon the uncapped weight assigned to the partition. Also entitled capacity is assigned to the partitions in the order, in which they start. The entitled capacity can be removed during DLPAR.