HP-UX Virtual Partitions Administrator Guide (includes A.05.07) (5900-1229, September 2010)

Memory: Specifying Address Range
Within the already allocated memory sizes, you can specify the memory address ranges using
the mem:::base:range syntax. However, this is not recommended unless you are familiar with
using memory addresses. You should also be familiar with the requirement that all HP-UX
kernels fit within 2 GB of memory, as described in “2 GB Restriction” (page 256).
For usage information, see the vparmodify(1M) manpage. You should select your base:range
after consulting vparstatus -A to determine which ranges are available.
NOTE: Specifying an address range does not increase the amount of memory assigned to the
partition. Rather, it only specifies addresses to use for the already allocated memory sizes.
Therefore, all specified ranges cannot exceed the total allocated memory for the virtual partition.
In other words, the sum of the ILM-specified ranges cannot exceed the total amount of ILM
memory reserved for the virtual partition.
2 GB Restriction
When ranges are specified for the entire memory owned by a partition, you should ensure that
at least one of the ranges is below 2 GB and is large enough to accommodate the kernel for that
partition. However, other partitions also require memory below 2 GB for their kernels. Hence,
you also should ensure that the specified range below 2 GB is not so large such as to preclude
memory below 2 GB for the other partitions.
In general terms, the sum of the size of the kernels must be < 2 GB. To calculate the kernel sizes,
see “Calculating the Size of Kernels in Memory (PA-RISC only)” (page 317).
CAUTION: Not allowing enough memory for the other partitions will cause the other partitions
to not boot. You can boot the partition by freeing up enough memory for the partition to boot,
such as by shutting down an active partition.
If no memory ranges are below 2 GBs for a given partition, the partition will not boot.
If you use the defaults of the dynamic tunables, you will not run into the 2 GB limit. However,
if you have adjusted the dynamic tunables, it is possible to run beyond the 2 GB boundary. For
more information on adjusting the kernel size with dynamic tunables, see the white paper
Dynamically Tunable Kernel Parameters at http://docs.hp.com.
256 CPU, Memory, and I/O Resources (A.03.xx)