Configuring and Migrating Memory on vPars

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Memory Categories
The vPars A.01.xx, A.02.xx and A.03.xx release streams support partitioning on HP-UX 11i v1
systems which only run on uniform memory systems (interleaved memory on cellular systems). The
vPars A.04.xx release steam supports partitioning on HP-UX 11i v2 systems which support memory
locality based optimizations on non-uniform memory access (NUMA) systems. The vPars A.05.xx
release supports partitioning on HP-UX 11i v3 systems which allow online addition and deletion of
memory. In these systems, the locality of the memory or the memory that can be online deleted later
has to be identified as such to the kernel when the partition is booted or when memory is added.
Hence, to allow users to control the type of memory that will be part of the partition, vPars supports
the following memory categories: interleaved memory (ILM), cell local memory (CLM), base memory,
and floating memory. The next section details ILM and CLM. The section after that explains base and
floating memory.
Interleaved and Cell Local Memory
HP-UX 11i v2 and later releases support memory locality based optimizations on NUMA systems. In
these systems the administrator can carve out portions of memory from one or more cells as cell local
memory. The remaining memory from all the cells that is not cell local memory is interleaved at cache
line granularity by firmware during system boot to create interleaved memory with average access
latency. The kernel creates one locality for each memory type with differing access latency,
transparently optimizes placement of data to minimize memory latency and provides APIs [1] to
applications to control the locality they want to use. The applications can take advantage of this by
using processors and memory from the same localities or localities that are close to each other to
achieve better performance.
In A.04.xx and A.05.xx vPars system, the system administrator has a choice of assigning ILM as well
as CLM between partitions. The vPars commands have separate options for ILM and CLM. The
legacy A.01.xx, A.02.xx and A.03.xx release vPars memory options would be considered as ILM. In
order for the user to specify the locality while performing memory operations with the vparcreate or
vparmodify commands, these commands have an additional option that takes the cell number as an
argument when specifying memory sizes. This option also provides the ability to tie processors from
the same locality to the partition. With a cell number, the memory and processors are considered as
cell local memory and cell local processors (CLP) to be allocated from the specified cell.
The system administrator has two choices: configure all the memory as ILM and manage it similar to
the way it was managed in A.01.xx, A.02.xx and A.03.xx release vPars systems or configure both
ILM and CLM and divide it among partitions. The following lists some of the steps that the system
administrator can use to create and use ILM and CLM in the vPars system:
1. Take inventory of the amount of ILM and CLM in each cell using the parstatus command.
# parstatus –p <hard partition number> –V
and
# parstatus –c <cell number> ... -V
2. Decide on the number of partitions, the amount of ILM for each partition, and the amount of
CLM for each partition and the cell or cells from which to allocate CLM.
3. Use parmodify to carve out CLM from cells. Cross-check through the parstatus command
that the required amount of CLM has been requested.
# parmodify –p <nPar > -m <cell number>::::<percentage CLM>% ...