Dynamic Logical Partitioning
Encyclopedia
Dynamic Logical Partitioning (DLPAR), is the capability of a logical partition
(LPAR) to be reconfigured dynamically, without having to shut down the operating system that runs in the LPAR. DLPAR enables memory, CPU capacity, and I/O interfaces to be moved nondisruptively between LPARs within the same server.
DLPAR has been supported by the operating systems AIX
and i5/OS on almost all POWER4 and follow-on POWER systems since then. The Linux kernel
for POWER also supported DLPAR, but its dynamic reconfiguration capabilities were limited to CPU capacity and PCI
devices, but not memory. In October 2009, seven years after the AIX announcement of DLPAR of memory, CPU and IO slots, Linux finally added the capability to DLPAR memory on POWER systems. The fundamentals of DLPAR are described in the IBM Systems Journal paper titled: "Dynamic reconfiguration: Basic building blocks for autonomic computing on IBM pSeries Servers.
Later on, the POWER5
processor added enhanced DLPAR capabilities, including micro-partitioning
: up to 10 LPARs can be configured per processor, with a single multiprocessor server supporting a maximum of 254 LPARs (and thus up to 254 independent operating system
instances).
There are many interesting applications of DLPAR capabilities. Primarily, it is used to build agile infrastructures, or to automate hardware system resource allocation, planning, and provisioning. This in turn results in increased system utilization. For example, memory, processor or I/O slots can be added, removed or moved to another LPAR, without rebooting the operating system or the application running in an LPAR. IBM DB2 is such application (http://www.ibm.com/developerworks/eserver/articles/db2_dlpar.html), it is aware of the DLPAR events and automatically tunes itself to changing LPAR resources.
The System z9
and zSeries
mainframes and their operating systems, including Linux on zSeries, support even more sophisticated forms of dynamic LPARs. Relevant LPAR-related features on those mainframe platforms include Intelligent Resource Director
, Sysplex, Parallel Sysplex
, Geographically Dispersed Parallel Sysplex, and Hipersockets. The System z9 supports up to 60 LPARs on a single server, but mainframes also support an additional level of virtualization using z/VM
with the ability to support thousands of operating system instances on a single server.
LPAR
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....
(LPAR) to be reconfigured dynamically, without having to shut down the operating system that runs in the LPAR. DLPAR enables memory, CPU capacity, and I/O interfaces to be moved nondisruptively between LPARs within the same server.
DLPAR has been supported by the operating systems AIX
AIX operating system
AIX AIX AIX (Advanced Interactive eXecutive, pronounced "a i ex" is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms...
and i5/OS on almost all POWER4 and follow-on POWER systems since then. The Linux kernel
Linux kernel
The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
for POWER also supported DLPAR, but its dynamic reconfiguration capabilities were limited to CPU capacity and PCI
Peripheral Component Interconnect
Conventional PCI is a computer bus for attaching hardware devices in a computer...
devices, but not memory. In October 2009, seven years after the AIX announcement of DLPAR of memory, CPU and IO slots, Linux finally added the capability to DLPAR memory on POWER systems. The fundamentals of DLPAR are described in the IBM Systems Journal paper titled: "Dynamic reconfiguration: Basic building blocks for autonomic computing on IBM pSeries Servers.
Later on, the POWER5
POWER5
The POWER5 is a microprocessor developed and fabricated by IBM. It is an improved version of the highly successful POWER4. The principal improvements are support for simultaneous multithreading and an on-die memory controller...
processor added enhanced DLPAR capabilities, including micro-partitioning
Micro-Partitioning
Micro-Partitioning is a form of logical partitioning which was introduced by IBM on systems using the POWER5 processor, and is also referred to as a shared processor partition, and only differs from a dedicated processor partition in the way CPU utilization is configured and managed by the POWER...
: up to 10 LPARs can be configured per processor, with a single multiprocessor server supporting a maximum of 254 LPARs (and thus up to 254 independent operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
instances).
There are many interesting applications of DLPAR capabilities. Primarily, it is used to build agile infrastructures, or to automate hardware system resource allocation, planning, and provisioning. This in turn results in increased system utilization. For example, memory, processor or I/O slots can be added, removed or moved to another LPAR, without rebooting the operating system or the application running in an LPAR. IBM DB2 is such application (http://www.ibm.com/developerworks/eserver/articles/db2_dlpar.html), it is aware of the DLPAR events and automatically tunes itself to changing LPAR resources.
The System z9
System z9
IBM System z9 is a line of IBM mainframe. It was announced on July 25, 2005 and the first models were available on September 16, 2005. The System z9 also marks the end of the previously used eServer zSeries naming convention, and it is the last z/Architecture 1 machine.- Background :System z9 is a...
and zSeries
ZSeries
IBM System z, or earlier IBM eServer zSeries, is a brand name designated by IBM to all its mainframe computers.In 2000, IBM rebranded the existing System/390 to IBM eServer zSeries with the e depicted in IBM's red trademarked symbol, but because no specific machine names were changed for...
mainframes and their operating systems, including Linux on zSeries, support even more sophisticated forms of dynamic LPARs. Relevant LPAR-related features on those mainframe platforms include Intelligent Resource Director
Intelligent Resource Director
On IBM mainframes running the z/OS operating system, Intelligent Resource Director is software that automates the management of CPU resources and certain I/O resources....
, Sysplex, Parallel Sysplex
IBM Parallel Sysplex
In computing, a Parallel Sysplex is a cluster of IBM mainframes acting together as a single system image with z/OS. Used for disaster recovery, Parallel Sysplex combines data sharing and parallel computing to allow a cluster of up to 32 systems to share a workload for high performance and high...
, Geographically Dispersed Parallel Sysplex, and Hipersockets. The System z9 supports up to 60 LPARs on a single server, but mainframes also support an additional level of virtualization using z/VM
Z/VM
z/VM is the current version in IBM's VM family of virtual machine operating systems. z/VM was first released in October 2000 and remains in active use and development . It is directly based on technology and concepts dating back to the 1960s, with IBM's CP/CMS on the IBM System/360-67...
with the ability to support thousands of operating system instances on a single server.
See also
- Virtualization
- OS-Level VirtualizationOperating system-level virtualizationOperating system-level virtualization is a server virtualization method where the kernel of an operating system allows for multiple isolated user-space instances, instead of just one. Such instances may look and feel like a real server, from the point of view of its owner...
- HypervisorHypervisorIn computing, a hypervisor, also called virtual machine manager , is one of many hardware virtualization techniques that allow multiple operating systems, termed guests, to run concurrently on a host computer. It is so named because it is conceptually one level higher than a supervisory program...
- Hipersockets
- OS-Level Virtualization
- Logical PartitioningLPARA 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....
- Micro-PartitioningMicro-PartitioningMicro-Partitioning is a form of logical partitioning which was introduced by IBM on systems using the POWER5 processor, and is also referred to as a shared processor partition, and only differs from a dedicated processor partition in the way CPU utilization is configured and managed by the POWER...
- Micro-Partitioning