[4] PR/SM (Processor Resource/System Manager) is a type-1 Hypervisor (a virtual machine monitor) that allows multiple logical partitions to share physical resources such as CPUs, memory, I/O channels and LAN interfaces; the LPARs can share I/O devices such as direct access storage devices (DASD).
[1]: 83 MDF-based LPAR technology continued to be developed separately by Amdahl, and Hitachi Data Systems in part for their implementations of the new ESA/370 architecture, which featured the introduction of access registers that allowed use of multiple data spaces addressable by a single address space.
DPM provides Web-based user interfaces for many LPAR-related configuration and monitoring tasks.
z/VM supports the z/Architecture HiperSockets function for high-speed TCP/IP communication among virtual machines and logical partitions (LPARs) within the same IBM zSeries server.
IBM introduced LPARs to their PowerPC-based AS/400 (later called iSeries) and pSeries servers in 1999 and 2001, respectively,[5] albeit with varying technical specifications.
In late 2011, Hitachi announced availability of CB2000 and CB320 blade systems,[7] which support LPAR on x86-64 hardware.
While on Amdahl's MDF (Multiple Domain Facility) it was possible to configure an LPAR with both shared and dedicated CPUs, this is no longer possible with any mainframes currently in the market.
All 64-bit IBM mainframes, except for the first generation 64-bit models (z900 and z800), operate exclusively in LPAR mode, even when there is only one partition on a machine.
[11] LPARs (with sufficient certification) 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.
IBM mainframe LPARs are Common Criteria EAL 5+ certifiable, equivalent to physically unconnected servers, so they support the highest security requirements, including military use.