HP-UX Virtual Partitions Administrator's Guide (includes A.05.02)

CPU, Memory, and I/O Resources (A.05.xx)
Memory: Granularity Issues (Integrity and PA-RISC)
Chapter 6
209
Memory: Granularity Issues (Integrity and PA-RISC)
CAUTION (vparcreate only) When you specify the granularity value for only one type of memory (ILM or
CLM), the granularity value for the other type of memory is set using the default granularity
value. For example, if you specify only -g ILM:256, the -g CLM:128 is implied where 128 is the
vPars default granularity value.
You should be careful when using the granularity option; using the option incorrectly can cause
all the virtual partitions to not be bootable.
Further, granularity in the vPars database can only be specified during the creation of the
vPars database. This means the first vparcreate command performed to create the database
can be used to specify the granularity, but it cannot be changed after that. It cannot be changed
by subsequent vparcreate commands nor any other commands; any change in values requires
the entire vPars database to be re-created. Therefore, please read this section thoroughly.
For details on granularity values and granularity limitations, see the vparresources (5)
manpage. The granularity section of this manpage contains critical notes which you should
know when planning a granularity value. These include:
• The minimum values for granularity of both ILM and CLM are 64 MB.
• The chosen granularity value(s) must be an integral power of 2 (in other words, 2^X).
• (Integrity only) There is a limit on the number of CLM granules per cell and total ILM
granules you can set. Use the vparenv command to see the maximum possible granules for
ILM and CLM for your specific system. For example:
# vparenv
vparenv: The next boot mode setting is "vPars".
vparenv: The ILM granule size setting is 128.
vparenv: The CLM granule size setting is 128.
vparenv: Note: Any changes in the above settings will become effective
only after the next system reboot.
vparenv: Note: The maximum possible CLM granules per cell is 64.
vparenv: Note: The maximum possible ILM granules for this system is 1024.
If either of these values are exceeded when you set your granularity values, the Monitor
will not boot any virtual partitions. You must rebuild your vPars database such that the
number of granules related to both ILM and CLM does not exceed the numbers in your
vparenv output.
• (PA-RISC only) Excluding the first granule, a portion of which is used by the Monitor, there
must be at least one entire granule that exists below the 2 GB limit for each virtual
partition. At least one granule below 2 GB is needed for the kernel in each virtual partition.
• (Integrity only) In a mixed HP-UX 11i v2/v3 vPars environment, the boot time of virtual
partitions running vPars A.04.xx will be greater if the nPartition contains more granules.
To reduce the boot time of the virtual partitions running vPars A.04.xx, increase the
granule size. The boot time of a virtual partition running vPars A.05.xx does not vary with
the number of granules.
• (Integrity only) In order for the virtual partitions in an active database to be able to boot,
the granularity values in the vPars database must match those written in the system
firmware.