IBM p5 550 Technical Overview And Introduction

Also see for p5 550: Technical overview and introduction

Contents

Chapter 2. Architecture and technical overview 33POWER5 systems introduce an enhanced partitioning model available as a hardwarefeature.The Micro-Partitioning model offers a virtualization method of system resources. In POWER5processor-based systems, physical resources are abstracted into virtual resources that areavailable to partitions. This sharing method is the primary feature of this new partitioningconcept and it happens automatically after a initial system setup.POWER5 Micro-Partitioning specifies processor capacity in processing units. One processingunit represents 1% of one physical processor. A Micro-partition defined with 220 processingunits is equivalent to the power of 2.2 physical processors. Creating a micro-partition, theminimum capacity is 10 processing units, or 1/10 of a physical processor. A maximum of 10micro-partitions for each physical processor can be defined, but on a loaded system thepracticle limit is less.Micro-partitions can also be defined with the capped and uncapped attributes. A cappedmicro-partition is not allowed to exceed the defined share, while an uncapped partition isallowed to consume additional capacity with fewer restrictions. Uncapped partitions can beconfigured to the total idle capacity of the server or a percentage of it. Configuration throughthe HMC menus sets the allowed share and the capped or uncapped attribute.The POWER5 processor-based systems use the POWER Hypervisor, which is the newactive Hypervisor to execute the Micro-partition model. The Hypervisor of existing POWER4processor-based systems is working on a demand basis, as the result of machine interruptsand callbacks to the operating system.The Advanced POWER Virtualization Feature (Virtual I/O Server) described in 2.10.1,“Advanced POWER Virtualization feature” on page 34, facilitates the understanding of all thePOWER5 and POWER Hypervisor enhancements to reach the highest level of granularity ofinstalled system resources.Figure 2-12 shows the Micro-partition LPAR concept.Figure 2-12 Micro-partition LPARMicro-PartitioningVirtual I/OServerAIX v5.3VirtualAdapterVirtualSCSILinux AIXv5.2AIXv5.3AIX v5.3AIX v5.3LinuxLinuxAIX v5.3AIX v5.3LinuxLinuxAIX v5.3AIX v5.3POWER HypervisorVirtual EthernetI/OStorage NetworkI/OSto NetI/OSto NetI/OSto Net HMC8 CPUs 2 CPUs 4 CPUs 4 CPUs 6 CPUsI/OS NnetworkExternalstorage