Locality-Optimized Resource Alignment

6
HP-UX 11i supports a variety of partitioning models. The sections that follow explain which of these
models are sensitive to the LORA configuration rules.
nPartitions
At the nPartition level, each base cell should be configured with ⅞
ths
local memory to comply with the
LORA configuration rules. The floating cells, if any, always have 100% local memory. The appendix
Configuring nPartitions for LORA contains more detail.
For nPartitions containing exactly one locality, there is no difference between interleaved memory and
local memory. For such a partition, there is no difference between SMP mode and LORA mode. If a
second cell were added via Dynamic nPartitions, then there would be a difference between the two
modes.
vPars
Each vPars instance should be composed with ⅞
ths
local memory and ⅛
th
ILM. Since the underlying
nPartition has this memory ratio, it is straightforward to reflect the same ratio into the vPars instances.
It is important that the processor and memory resources assigned to each vPars instance span the
minimal set of localities. If a vPars instance must span multiple localities, then the processor and
memory resources should be distributed symmetrically across those localities. Aligning I/O resources
with the processors and memory is helpful, but it is a second-order effect. The appendix
Configuring
vPars for LORA explains these points in more detail.
HP recommends that vPars instances configured with ⅞
ths
local memory be operated in LORA mode.
This can be achieved most easily by leaving the numa_mode parameter at its default value. When
vPars is operating in LORA mode, the system will manage any CPU migration operations so as to
adhere as closely as possible to the configuration rules given above.
Integrity Virtual Machines
The nPartition containing the Integrity Virtual Machines host should be composed with ⅞
ths
local
memory and ⅛
th
ILM. The guest instances operate in a Uniform Memory Architecture environment, so
it is neither necessary nor possible to configure local memory in the guest instances. The Integrity
Virtual Machines host will allocate resources to the guest instances to gain the greatest possible
benefit from memory local to the processors.
LORA system administration
For the most part, managing a system in LORA mode is identical to managing it in SMP mode.
Suggestions for adapting to unusual workload profiles are in the
Advanced Tuning appendix.
Server Tunables product in the Tune-N-Tools bundle
We recommend using the Server Tunables product in the Tune-N-Tools bundle with LORA to improve
application performance. This product was introduced with Update 3 and is also available on the
web in the HP ‘software depot’:
http://h20392.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=Tune-N-Tools
loratune command
The loratune command is valuable in LORA mode. The command can be used to restore good
resource alignment if it has been disturbed by an event such as