Installing and Managing HP-UX Virtual Partitions (includes A.04.02)

Appendix B
267
B Problem with Adding Unbound CPUs to a
Virtual Partition (A.03.xx)
Unbound CPUs allow you to easily adjust processing power between virtual partitions. But a corner case can
occur where you will not be able to add specific unbound CPU(s) without rebooting the target partition. This
appendix discusses when this situation can occur and how to work around it.
Symptoms
When attempting to add an unbound CPU, you may see the following error message:
One or more unbound CPUs were not available when virtual partition <partition_name> was
booted. You must shutdown the partition to add them.
This means that the unbound CPU cannot be dynamically added to the virtual partition.
Cause
When a virtual partition boots, the HP-UX kernel creates a table of the existing unbound CPUs available at
the time the virtual partition is booted. If there is not an existing entry in the table for a specific CPU, that
CPU cannot be added to the partition.
Example
To simplify the example, this appendix uses a generic eight-way (8-processor) server whose processors are at
the hypothetical hardware paths of x01, x02, x03, x04, x05, x06, x07, and x08.
Create the Virtual Partitions
Suppose we create three partitions using the following commands.
# vparcreate -p vpar1 -a cpu::2 -a cpu:::2
# vparcreate -p vpar2 -a cpu::2 -a cpu:::2
# vparcreate -p vpar3 -a cpu::1
And suppose that the Monitor chooses the following hardware paths for the bound CPUs:
This configuration leaves the following three CPUs as unbound CPUs:
Virtual Partition vpar1 vpar2 vpar3
Paths of Bound
CPU(s)
x01
x02
x03
x04
x05
Paths of
Unbound CPUs
x06, x07, x08