Dynamic reconfiguration: Basic building blocks for autonomic computing on IBM pSeries servers
Joefon Jann, L. M. Browning, R. Sarma Burugula · IBM Systems Journal · 2003
A Logical Partition (LPAR) in an IBM pSeries™ Symmetric Multiprocessor (SMP) system is a subset of the hardware of the SMP that can host an OS instance. Dynamic Reconfiguration (DR) on these logically partitioned servers enables the movement of hardware resources (such as processors, memory, and I/O slots) from one logical partition to another without requiring reboots. This capability also enables an autonomic agent to monitor usage of the partitions and automatically move hardware resources to a needy OS instance non-disruptively. Nowadays, as SMPs and NUMA systems get larger and larger, the ability to run several instances of an Operating System[s] on a given hardware system, so that each OS instance plus its subsystems scale or perform well, provides the advantage of optimal aggregate performance, which can translate to cost savings for the customers. Though static partitioning provides a solution to this overall performance optimization problem, DR enables an improved solution by providing the capability to dynamically move hardware resources to a needy OS instance in a timely fashion to match the workload demands. Hence DR capabilities serve as key building blocks for workload managers to provide self-opimizing and self-configuring features. Besides dynamic resource balancing, DR also enables dynamic capacity upgrade on demand, and self-healing features such as dynamic CPU sparing, a winning solution for users in this age of rapid growth in Web servers on the Internet.