Friday, December 3, 2010

Logical partition (virtual computing platform)

A logical partition, commonly called an LPAR, is a subset of computer's hardware resources, virtualized as a separate computer. In effect, a physical machine can be partitioned into multiple logical partitions, each hosting a separate operating system.
The terms PR/SM and LPAR are often used interchangeably
PR/SM is a type-1 hypervisor that runs directly on the CPU. PR/SM allocates system resources and allows multiple logical partitions to share physical resources such as CPUs, direct access storage device (DASD), and memory.
The changing of resource allocations without restart of the logical partition is called dynamic logical partitioning.
LPARs safely allow combining multiple test, development, quality assurance, and production work on the same server, offering advantages such as lower costs, faster deployment, and more convenience.