HP-UX Virtual Partitions Administrator's Guide (includes A.03.05 and A.04.05)

Memory: Allocation Notes
• 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 Install and Upgrade Guide for your OS and the nPartition
Administrator’s Guide for your server.
• The unit for the specified size of memory for the vPars commands is megabytes; parmodify
uses gigabytes.
• Memory is allocated in multiples of 128 MB by default. Memory assignments are also rounded
up (to the next highest granule boundary).
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 and
dual-core Intel Itanium processors, 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.
• “Cell local processor (CLP),” which refers to a CPU (core) on a specified cell.
For more information on dual-core processors, see “CPU: Dual-Core Processors” (page 234).
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.04.01 and later, the two types of CPUs are Boot Processor and dynamic CPUs. This
discussion begins at “CPU: Boot Processor and Dynamic CPU Definitions ” (page 227). The bound
and unbound CPU types in vPars A.03.xx and earlier no longer apply.
For additional information on using iCAP (formerly known as iCOD), including temporary-iCAP
CPUs with vPars, see “CPU: Using iCAP (Instant Capacity on Demand) with vPars (vPars A.04.xx
and iCAP B.07)” (page 232).
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.
For more information, see “CPU: Syntax, Rules, and Notes” (page 231).
226 CPU, Memory, and I/O Resources (A.04.xx)