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

Memory: Allocation Concepts and Notes
• The unit for the specified size of memory for the vPars commands is megabytes; parmodify
uses gigabytes.
• The default memory assigned to a virtual partition is 0 MB, so you need to specify enough
memory for your applications and the operating system. While there is no specific minimum
base memory requirement per vpar, the HPUX kernel does require a certain amount of base
memory to boot successfully. For this reason, we currently recommend that 1 GB of base
memory is assigned per vpar. The more base memory a virtual partition has, the better the
performance will be. This is especially true of applications that require large amounts of
locked memory. See the Installation and Update Guide for your OS and the nPartition
Administrator’s Guide for your server.
• Memory is allocated in multiples of 64 MB. Any specified size that is not a multiple of 64
MB is rounded up to the nearest 64 MB boundary. For example, if you specify 1 MB, 64 MB
will be allocated.
CPU
NOTE:
Processor Terminology Processing resources under vPars, both as input arguments and command
outputs, are described as “CPUs.” For multi-core processors such as the PA-8800, the term “CPU”
is synonymous with “core.” The term “processor” refers to the hardware component that plugs
into a processor socket. Therefore a single processor can have more than one core, and vPars
commands will refer to the separate cores as distinct “CPUs,” each with its own hardware path.
Two vPars terms pre-date multi-core processors, so they are exceptions to this terminology:
• “boot processor,” which refers to the CPU (that is, core) on which the OS kernel of the virtual
partition was booted, and
• “cell local processor (CLP),” which refers to a CPU on a specified cell.
For more information on dual-core processors, see “CPU: Dual-Core Processors” (page 265).
CPU migration refers to adding CPUs to and deleting CPUs from a virtual partition. Dynamic
CPU migration refers to migrating CPUs while the target virtual partition is running. vPars allows
the assignment of most CPUs while the virtual partitions are running.
For vPars A.03 and earlier, the two types of CPUs are bound and unbound (floater) CPUs. This
discussion begins at “CPU: Bound and Unbound” (page 259).
NOTE:
Using vPars A.03.xx and Earlier Syntax on a vPars A.04.xx System Although not recommended
under most circumstances, you can still use the vPars A.03.xx CPU syntax on vPars A.04.xx
systems. However, the concepts and rules of boot processors and dynamic CPUs in A.04.xx will
apply because the concepts and rules of bound and unbound CPUs in A.03.xx no longer apply.
Memory: Allocation Concepts and Notes 257