LPAR operating system considerations

There are several issues to consider about LPAR operating systems.

Partitions on POWER4-based systems can run on the following operating systems:

• AIX operating system with a 32-bit kernel.
• AIX® with a 64-bit kernel. The AIX 64-bit kernel is optimized for running 64-bit applications and improves scalability by allowing applications to use larger sizes of physical memory assigned to that partition.
• Linux® with a 64-bit kernel.

Each of the partitions on a system can run a different level of an operating system. Partitions are designed to isolate software running in one partition from software running in the other partitions. This includes protection against natural software breaks and deliberate software attempts to break the LPAR barrier. Data access between partitions is prevented, other than normal network connectivity access. A software partition crash in one partition will not cause a disruption to other partitions, including failures for both application software and operating system software. Partitions cannot make extensive use of an underlying hardware shared resource to the point where other partitions using that resource become starved, for example partitions sharing the same PCI bridge chips are not able to lock the bus indefinitely.