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

CPU, Memory, and I/O Resources (A.03.xx)

Memory: Specifying Address Range

Chapter 8

284

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” on page 284.

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)” on page 357.

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.