HP Instant Capacity Version 10.x User Guide (5900-1581, March 2011)

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. 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 Instant Capacity 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 are making any adjustment to an nPartition or to multiple nPartitions. When
you execute the icapmodify command to deactivate a core, the Instant Capacity 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 Instant Capacity
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 Instant Capacity 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 Instant Capacity 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. 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 Instant Capacity 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 Instant Capacity intended active count for the nPartition.
Example 8 shows a sample boot-time compliance message sent when a virtual partition is prevented
from booting.
48 Using Instant Capacity to Manage Processing Capacity