HP Instant Capacity User's Guide for Versions 8.x

Activating Cores
The icapmodify command provides the ability to increase processing capacity instantly by
activating cores with available usage rights in nPartitions (hard partitions) of Instant Capacity
systems. At any time, any number of inactive cores with usage rights can be activated, as long
as sufficient usage rights are available. See “Instant Capacity Integration with Virtual Partitions
(HP-UX only)” (page 179) for details about activation in virtual partitions.
Activating Cores in nPartitions
The software provides two types of activation:
• Instant ( icapmodify command’s default behavior) — the activation occurs immediately
• Deferred ( icapmodify command’s -D option) — the activation occurs after the next reboot
of the partition
Instant activation of cores occurs when the icapmodify command is used with either the -a
or -s option, and the -D option is not specified.
Deferred activation of cores occurs when the icapmodify command is used with both the -D
option and either the -a or -s option specified. With the deferred option (-D), core activation
occurs after a reboot of the partition. The scheduled timing of the reboot (and the core activation)
can take place at a planned time. For example, if you activate cores in deferred activation mode
and schedule a partition reboot to occur on the first day of the next month, the cores are activated
at that time.
IMPORTANT: If you shut down a partition for 12 hours or more, you should also power it off
to avoid additional charges. To power off the partition, execute the PE command from the system
MP.
On HP-UX systems, always use the shutdown -R -H command when shutting down or
rebooting an Instant Capacity partition, or if the partition is already shutdown, use the rr
command from the system MP to reset cells for reconfigure. See the HP-UX manpage shutdown(1M)
for information on the shutdown command.
On OpenVMS systems, always use the sys$system:shutdown.com procedure when shutting
down or rebooting an Instant Capacity partition.
While a deferred activation does not immediately change the number of active cores, the Intended
Active value is changed which does affect compliance checking, even before the partition reboot
occurs. In particular, compliance checking is calculated as if the activation had not been deferred.
IMPORTANT: On OpenVMS iCAP systems, HP strongly recommends that you activate cores
using the icapmodify or the ICAP SET command. The use of the START CPU command on
an iCAP system may result in unintended consequences, such as a reduction of available
temporary capacity. Another unintended side effect may be the adjustment in core usage across
the complex depending on the intended core settings on the partition where the START CPU
command was issued.
To activate one or more inactive cores, use the icapmodify command as root. See the HP-UX
manpage icapmodify((1M)) for details.
Activating Cores 59