HP Superdome 2 Partitioning Administrator Guide

Memory Granularity
The nPartition memory is divided into multiple memory granules by firmware for ease of memory
assignment to vPars. The size of these memory granules can be optionally specified by the user.
Memory granularity refers to the size of these memory granules. Note that memory granules
are not the actual memory DIMMs.
The granularity for SLM and ILM are specified separately by the user. However, the following
applies to both types of memory:
• Memory granularity is specified at nPartition creation time. Any modification thereafter
requires a reboot of the nPartition.
• The minimum values (ILM and SLM granularity) are 256 MB.
• The default value is OS dependent and may be adjusted based on the total memory available
in the nPartition.
• Memory is assigned to virtual partitions in multiples of granule sizes.
HP recommends not to change the default memory granularity value chosen by the system,
unless there is a specific need to do that.
Assigning Memory to a vPar
• The -a mem::size option is used to assign size megabytes of ILM to a vPar.
• The -a socket:socket_id:mem::size option assigns size megabytes of SLM from
socket socket_id to a vPar.
If size is not an integral multiple of the granularity of the specified memory type, vPars normally
adjusts it upward to the next granule boundary.
In a vPar environment, either of the above command line options will cause the system to reserve
the indicated memory, if it is available. Thus, it is possible to define vPars with more memory
in them than is in the entire nPartition. Actual memory ranges are only assigned to the vPar
when it is booted. These ranges may be different from boot to boot.
I/O
The vPar assignable IO resources are rootports or ioslots in the blades and I/O bays. Rootports
and ioslots are two different ways of representing I/O resources. The parstatus -c
enclosure#/blade# -V command provides the rootport to ioslot mapping for the I/O resources
on a blade. Similarly, the parstatus -i IOX#/IObay# -V command provides the rootport
to ioslot mapping for the I/O resources in an I/O bay. Rootports and ioslots have a one-to-one
mapping and either of them can be assigned to a vPar. The rootport (RP) or ioslot is specified in
the resource path format. Typically disk devices or LAN devices get attached to a rootport. On
blades, iLO is also off a rootport. There is a one-to-one mapping between the rootport and the
I/O slot on HP Integrity Superdome 2 servers.
Assigning I/O at the rootport or I/O slot Level
You can run the vparcreate and vparmodify commands with either of these parameters:
rootport resourcepath format: -a io:9/1/0/0/2
or
ioslot resource path format: -a ioslot:9/1/3
A vPartition may be created at the OA with the following command:
vparcreate -N5 –p1 -a cpu::4 -a mem::6000 -a ioslot:9/1/3
To verify that the resulting vPartition had the expected IO in that slot, install and boot HP-UX
in that partition and then run ioscan -m resourcepath, searching for the ioslot number:
# ioscan -m resourcepath | grep 9/1/3
78 Planning Your System for Virtual Partitions