HP-UX Virtual Partitions Administrator's Guide (includes A.04.06 and A.05.04)

Deleting CPUs Summary
• You can delete any CPU, except the current boot processor, by specifying its hardware path.
• If you want to control which CPU is deleted (rather than leaving it up to the vPars Monitor),
use the same method—by CLP, by hardware path, or by count—on your deletion command
line that you used on your addition command line.
• The current boot processor can not be deleted from a virtual partition. (Use vparstatus
-v to determine the current boot processor.) You will need to shutdown the virtual partition
and delete the desired CPU.
Managing I/O Interrupts
This section describes information you need if you are managing I/O interrupts on a vPars-enabled
system. Note that migrating interrupts should only be done by advanced administrators for
performance tuning.
intctl Command
The intctl command is a HP-UX tool that allows you to manage I/O interrupts among active
CPUs.
For HP-UX 11i v2 and later, the software for intctl is part of the Core OS.
For more information, see the Interrupt Migration Product Note available at http://docs.hp.com
or the intctl(1M) manpage.
Notes
• At boot time of a virtual partition, interrupts are processed by all the CPUs in the virtual
partition.
• After boot, CPUs that are added to the virtual partition are not assigned to process I/O
interrupts. However, you can migrate I/O interrupts to any added CPU using intctl.
• After boot, CPUs that are deleted from a virtual partition no longer process I/O interrupts
for the partition. When a CPU is deleted from a virtual partition, if the deleted CPU has I/O
interrupts, the I/O interrupts are automatically and transparently reassigned to other active
CPUs in the partition.
NOTE: Repeatedly adding and deleting CPUs without a reboot of the target virtual partition
may cause an imbalance in the interrupt processing load across the CPUs of the virtual partition.
However, you can use intctl to rectify the imbalance if necessary.
CPU: Using iCAP (Instant Capacity on Demand) with vPars (vPars A.04.xx
and iCAP B.07)
iCAP CPUs are unlicensed CPUs. The unlicensed CPUs may be shown as available CPUs in the
vparstatus -A output. To use iCAP CPUs, you must first purchase them; then, you can activate
and assign them to a virtual partition.
For detailed information on using iCAP in vPars environment, including using earlier versions
of iCAP (formerly known as iCOD) with earlier versions of vPars, see the corresponding HP
Instant Capacity User’s Guide.
Purchasing Licenses for iCAP CPUs
To purchase licenses for any iCAP components, including iCAP CPUs, you must follow the
normal iCAP process as shown in the HP Instant Capacity User’s Guide. If you attempt to assign
an iCAP CPU before purchasing the license, you will get an iCAP authorization error.
Managing I/O Interrupts 237