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

application might not recognize the newly activated core as available for processing. Therefore,
you might need to do one of the following for optimal performance with this type of application:
• Restart the application in order for it to recognize the presence of newly activated cores.
• Reconfigure the application prior to restarting it, for maximum performance benefits of the
newly activated core.
• Use the deferred activation option when activating cores so that processors are activated only
in conjunction with system reboots. For details, see icapmodify(1M) for details
IMPORTANT: When you activate a core, the number of active cores in the system increases.
Consequently, a license upgrade might be required for some of the software from HP or other
vendors on your system.
Test activation of cores using temporary capacity
You might want to test your software application for proper operation and improved performance
by activating an additional core. The use of temporary capacity or Instant Access Capacity (IAC)
is required for activation of a core without usage rights for testing purposes. For details, see
Chapter 5: “TiCAP” (page 52).
The following testing guidelines are meant to be an aid to your test plan. You might need to get
consulting help to develop a more detailed plan.
1. Test your applications for proper functionality and performance first by testing with the number
of inactive cores equal to the number of cores without usage rights. (The system should already
be configured this way.) Be sure to check measurement tools that monitor core usage.
2. Acquire temporary capacity for the necessary amount of core test activation.
3. Use temporary capacity to activate one or more inactive cores to be used while your
applications are running.
4. Confirm that measurement tools, which monitor processing usage, account for the newly
activated cores.
5. Verify that applications are benefiting from the performance of the extra cores (as per your
expectations for your applications). Some applications might need to be restarted or
reconfigured to take advantage of the newly activated cores.
6. When you are finished with your testing, deactivate cores until the number of inactive cores
again matches the number of cores without usage rights, thereby stopping the usage of
temporary capacity.
7. Use icapstatus to verify that no cores are consuming temporary capacity.
Replacement of failed cores
HP-UX LPMC and HPMC
If an active core fails with a Low Priority Machine Check (LPMC) in a partition with iCAP, its
processing capacity is replaced instantly by an inactive core, if any are available in the partition.
The failed core is marked for deconfiguration during the next system reboot.
For additional considerations in a virtual partition environment, see “LPMC deactivations in vPars”
(page 51).
If an active core fails with a High Priority Machine Check (HPMC), then upon reboot the failed
core is deconfigured and its processing capacity is instantly replaced by an inactive core, if any
are available in the partition.
NOTE: In both of the preceding scenarios, replace the failed core in a timely manner using your
normal hardware support process.
50 Using iCAP to manage processing capacity