Guidelines for Configuring Virtual Partitions on Cellular Platforms

Configuration Flexibility Versus Resource Locality

Any valid virtual partition needs a set of resources assigned to it to enable it to host an HP-

UX Operating Environment and workload(s). The following is a brief overview of the types of

choices available for picking resources for assignments to virtual partitions or setting

attributes at the nPartition and the virtual partition level.

The granularity of processor assignment to a virtual partition is a CPU core. CPU cores can

be specified for assignment using one or more of the following methods:

• a count of CPU cores or

• a count of CPU cores from a given cell (CLPs: cell local processors) or

• Hardware path of the CPU.

CPU cores can also be dynamically migrated in or out of a virtual partition OS instance. For

more information on guidelines for CPU assignments please refer to [3].

The unit of memory assignment to a virtual partition is a granule, the size of which can be

specified as an attribute when the first virtual partition in an nPartition is created [5].

Memory, either cell local memory (CLM) from a specific cell and/or interleaved memory

(ILM) can be assigned to a virtual partition by specifying either:

• an amount of memory (in MB) and/or

• an explicit memory address and the size of the range specification

With HP-UX 11i v3 and beginning with the vPars A.05.01 release, the vPars software

supports dynamic addition of memory granules to an active virtual partition as either base or

floating memory and deletion of memory granules that were marked as floating from an

active virtual partition. Attributes like base and floating memory can be specified at the

individual virtual partition level to help the HP-UX kernel decide how much of the assigned

CLM or the ILM could be treated as ejectable and non-ejectable from the virtual partition.

For more information on guidelines for memory assignments and memory migrations please

refer to [4].

The minimum granularity of I/O assignment is a Local Bus Adapter (LBA) which translates to

a single I/O slot on the cellular platforms. I/O assignments are specified by their hardware

paths. Any available I/O slot (or LBA) in an nPartition can be assigned to any virtual

partition.

Given the wide range of options available for specifying resource assignments to virtual

partitions and the varying needs of each workload, a typical user is often faced with a

difficult task of planning a vPars environment that has:

(a) Enough resources to satisfy the needs of the workloads hosted in individual virtual

partitions, and

(b) A resource layout that ensures good workload performance.