IBM REDPAPER 520Q, Technical Overview And Introduction

Page: 65 / 110

Chapter 2. Architecture and technical overview
51
2.12 Advanced POWER Virtualization feature
The Advanced POWER Virtualization feature (FC 7940) is an optional, additional cost feature.
This feature enables the implementation of more fine-grained virtual partitions on IBM
System p5 servers.
The Advanced POWER Virtualization feature includes:
򐂰 Firmware enablement for Micro-Partitioning technology.
Support for up to 10 partitions per processor using 1/100 of the processor granularity.
Minimum CPU requirement per partition is 1/10. All processors are enabled for
micro-partitions (the number of processors on the system equals the number of Advanced
POWER Virtualization features ordered).
򐂰 Installation image for the Virtual I/O Server software that is shipped as a system image on
DVD. Client partitions can be either AIX 5L Version 5.3 or Linux. It supports:
– Ethernet adapter sharing (Ethernet bridge from virtual Ethernet to external network).
– Virtual SCSI Server.
– Partition management using Integrated Virtualization Manager (Virtual I/O Server
Version 1.2 or later only).
򐂰 Partition Load Manager (AIX 5L Version 5.3 only)
– Automated CPU and memory reconfiguration.
– Real-time partition configuration and load statistics.
– Graphical user interface.
For more details about Advanced POWER Virtualization and virtualization in general, see:
http://www.ibm.com/servers/eserver/pseries/ondemand/ve/resources.html
2.12.1 Micro-Partitioning technology
The concept of Micro-Partitioning technology allows you to allocate fractions of processors to
the partition. The Micro-Partitioning technology is only available with POWER5 and
processor-based systems. From an operating system perspective, a virtual
processor cannot be distinguished from a physical processor, unless the operating system
has been enhanced to be made aware of the difference. Physical processors are abstracted
into virtual processors that are available to partitions. See 2.12.2, “Logical, virtual, and
physical processor mapping” on page 52 for more details.
When defining a shared partition, you have to define several options:
򐂰 Minimum, desired, and maximum processing units. Processing units are defined as the
processing power, or the fraction of time, that the partition is dispatched on physical
processors.
򐂰
The processing sharing mode, either capped or uncapped.
򐂰 Weight (preference) in the case of an uncapped partition.
򐂰
Minimum, desired, and maximum number of virtual processors.
POWER Hypervisor calculates a partition’s processing entitlement based on its desired
processing units and logical processor settings, sharing mode, and also based on other
active partitions’ requirements. The actual entitlement is never smaller than the desired
processing unit’s value and can exceed the desired processing unit’s value if the LPAR is an
uncapped partition.