HP Instant Capacity Version 10.x User Guide (762794-001, March 2014)

efficient way to adjust capacity within virtual partitions of a single nPartition, but it does not affect
the intended active count for the nPartition. Therefore, it cannot be used to migrate unused capacity
either to or from other nPartitions. When you execute the vparmodify command to activate a
core, the command verifies with the iCAP software how many cores are available for activation.
This number is calculated as the difference between the local nPartition’s intended active number
and the total number of cores assigned to the vPars database.
Deactivating cores in a virtual partition environment
In a virtual partition environment, the icapmodify command must be used to modify processing
capacity when you make any adjustment to an nPartition or to multiple nPartitions. When you
execute the icapmodify command to deactivate a core, the iCAP software verifies that the request
can be satisfied. If so, the local nPartition’s intended active number is decreased, and the
appropriate number of cores are removed from the local virtual partition.
When the icapmodify command is used in a virtual partition, it checks with the iCAP software
to determine how many cores are available for deactivation. This number is calculated as the
difference between the local nPartition’s intended active number and the total number of cores
assigned to the vPars database. If there is any unused capacity available prior to the deactivation,
the result is that the actual active count changes by more than the intended active count, and the
intended active count may not change at all. However, the discrepancy between intended active
and actual active is reduced.
If you are adjusting core assignments across virtual partitions in a single nPartition, use the
vparmodify command for the best coordination between the iCAP software and the vPars
software, and for optimized performance. The vparmodify command is the fastest and most
efficient way to adjust capacity within virtual partitions of a single nPartition, but it does not affect
the intended active count for the nPartition and it therefore cannot be used to migrate unused
capacity either to or from other nPartitions. When you execute the vparmodify command to
deactivate a core, authorization is not required from the iCAP software.
Whether you are activating or deactivating cores, the icapmodify command adjusts only the
number of dynamic cores, and it does not explicitly identify specific cores.
Boot time compliance
A compliance check is performed whenever a virtual partition is booted (powered-on). If the total
number of cores assigned to all virtual partitions in the current vPar database exceeds the nPartition’s
intended active core count, the iCAP software notifies the vPar monitor. The monitor prevents any
virtual partition from booting until the user first performs a hard partition boot and then modifies
either the vPar configuration or the iCAP intended active count for the nPartition. Example 8 shows
a sample boot-time compliance message sent when a virtual partition is prevented from booting.
46 Using iCAP to manage processing capacity