Chapter 3. Virtualization
117
3.5.1 Dynamic logical partitions
Logical partitioning technology allows you to divide a single physical system into separate
logical partitions (LPARs). Each LPAR receives a user specified allocation of dedicated
computing resources, such as:
Processors (whole CPU increments)
Memory (16 to 256MB increments, depending on memory configured)
PCI slots and I/O components (individual slots or components)
The Hypervisor presents a collection of these resources as a
virtualized machine
to the
supported operating environment of your choice.
Logical partitioning was introduced with System p POWER4™ servers and the AIX 5L
Version 5.1 operating system. Logical partitioning was introduced on System i models prior to
POWER4 and IBM i (then known as OS/400) V4.5. LPAR is remains a valid option for
configuring LPARs on the 595 server
Later, dynamic logical partitioning (DLPAR) became available, which increased flexibility by
allowing system resources (processors, memory, and I/O components) to be dynamically
added or removed from the running LPARs. Dynamic reconfiguration of partitions allows
system administrators to move system resources between LPARs as necessary to satisfy
application performance requirements and to improve utilization of system resources. DLPAR
capabilities became available on POWER4 based servers running AIX 5L Version 5.2 and
IBM i 5.3. shows to LPAR with dedicated processing resources. Figure 3-1 shows LPAR #1
and LPAR #2 configured as dedicated processor LPARs.
Figure 3-1 Logical partitioning processor allocation options
3.5.2 Shared processor pool partitions
IBM Micro-Partitioning technology (introduced with POWER5 systems) allows you to allocate
processors with a finer granularity than with the basic logical partition. Processor allocations
can now be specified in hundredths of a cpu and can start as small as one tenth of a cpu.
Processing resources for these logical partitions are sourced from the shared processor pool
which is comprised of all activated processors that are not currently allocated to running
dedicated processor LPARs.
Logical partitions, which source their processing resources from the shared processor pool,
are known as shared processor LPARs (SPLPAR). A maximum of ten SPLPARs can be
configured per processor or a maximum 254 SPLPARs per 595 server. An important point is
LPAR
#1
LPAR
#2
SPLPAR
#3
SPLPAR
#4
SPLPAR
#5
SPLPAR
#6
SPLPAR
#7
SPLPAR
#8
Hypervisor
Shared Processor Pool
PU = 1.2
V
V
PU = 0.5
V
PU = 1.5
V
V
PU = 0.1
V
PU = 1.2
V
V
PU = 1.2
V
V
V
Core
Core Core
Core
Core
Core
Core
Core
Core
Core
Core
Core
1 Core
(dedicated)
2 Cores
(dedicated)
LPAR
#1
LPAR
#2
SPLPAR
#3
SPLPAR
#4
SPLPAR
#5
SPLPAR
#6
SPLPAR
#7
SPLPAR
#8
Hypervisor
Shared Processor Pool
PU = 1.2
V
V
PU = 0.5
V
PU = 1.5
V
V
PU = 0.1
V
PU = 1.2
V
V
PU = 1.2
V
V
V
Core
Core Core
Core
Core
Core
Core
Core
Core
Core
Core
Core
1 Core
(dedicated)
2 Cores
(dedicated)
Summary of Contents for Power 595
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