HP-UX Virtual Partitions Administrator Guide (includes A.05.09) (5900-2188, March 2012)

Example
• To add the CPUs at 0/10 and 0/11 to keira2:
keira1# vparmodify -p keira2 -a cpu:0/10 -a cpu:0/11
Using both the Hardware Path Specification and CLP specification
Although you can add and delete CPUs by hardware path, to avoid confusion it is recommended
that you specify by cell rather than by hardware path. The exception is for dual-CPU sockets.
For dual-CPU sockets, if you wish to have both CPUs of a socket assigned to the same virtual
partition, you should specify by hardware path instead of by cell. Specifying by cell cannot
guarantee that both CPUs in the socket are the CPUs chosen by the vPars Monitor and assigned
to the target virtual partition., although the vPars Monitor will attempt to do this whenever possible.
For more information on dual-core CPU usage, see “CPU: Dual-Core Processors” (page 221).
CPU: Syntax, Rules, and Notes
vparstatus
• When a virtual partition is down, vparstatus does not show any CPU assigned as the boot
processor. The boot processor is not assigned until the virtual partition is actually booted.
• If a virtual partition is down and assigned only one CPU, a CPU will be reserved by the vPars
Monitor, making it unavailable. The specific CPU reserved is not determined until boot time.
As a result, while the virtual partition is down, vparstatus -A, which shows available
resources, will show all the possible paths of unassigned CPUs but the count of available CPUs
will be one less. The count reflects the actual number of available CPUs because one CPU is
reserved for the down virtual partition.
Counts Summary
• At all times, the rule of min<=total<=max is enforced.
• When adding by CLP, the total count changes whether the partition is up or down.
• When adding by hardware path, the total count changes only when the partition is up. The
total does not change if the specified CPU is already assigned to the partition.
• When adding by hardware path and the partition is down, you cannot have the number of
CPUs added by hardware path exceed the current total value.
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.
CPU: Syntax, Rules, and Notes 219