IBM PowerVM - Introduction

1. What is a partition

Physical partition:

• Resources are allocated in physical building blocks.

• Blocks contain groups of processors, memory, and I/O slots

Logical partition

• A partition is the allocation of system resources to create logically separate systems within the same physical footprint.

• A logical partition exists when the isolation is implemented with firmware:

• Not based on physical system building block

• Provides configuration flexibility

Partition characteristics

Each partition has its own:

• Operating system

• Licensed internal code (LIC) and open firmware

• Console

• Resources

• Other things expected in a stand-alone operating system environment, such as:

• Problem logs

• Data (libraries, objects, file systems)

• Performance characteristics

• Network identity

• Date and time

• Resources are allocated to partitions:

• Memory allocated in units as small as the LMB size.

• Dedicated whole processors or shared processing units.

• Individual I/O slots.

• Including virtual devices

• Some resources can be shared:

• Virtual devices.

• Host Ethernet adapter.

• Some core system components are inherently shared

Benefits of using partitions

• Capacity management:

• Flexibility to allocate resources.

• Consolidation:

• Consolidate hardware, floor space, software licenses, support contracts, and in-house support and operations.

• Efficient use of resources.

• Application isolation on a single frame:

• Separate workloads.

• Guaranteed resources.

• Data integrity.

• Merge production and test environments:

• Test on same hardware

2. POWER Hypervisor functions

• The POWER Hypervisor is firmware that provides:

• Virtual memory management:

• Controls page table and I/O access.

• Manages real memory addresses versus offset memory addresses.

• Virtual console support

• Security and isolation between partitions:

• Partitions allowed access only to resources allocated to them (enforced by the POWER Hypervisor).

• Shared processor pool management

3. Advanced partition

Dynamic Logical Partitioning (DLPAR)

• DLPAR is the ability to add, remove, or move resources between partitions without restarting the partitions.

• Resources include:

• Processors, memory, and I/O slots.

• Add and remove virtual devices.

• Security and isolation between LPARs are not compromised.

• A partition sees its own resources plus other available virtual resources.

• Resources are reset when moved.

• Applications might or might not be DLPAR-aware

Processor concepts

Micro-partitioning: Shared processor pool

• Time sliced sub-processor allocations are dispatched according to demand and entitled capacity.

• This example shows one 10 ms time slice, seven running partitions, and four processors

Multiple shared processor pools

Virtual I/O

• Each partition has virtual I/O slots.

• Configurable for each partition.

• Virtual slots have a virtual adapter instance.

• Serial, Ethernet, SCSI, or Fibre Channel.

• Virtual I/O slots can be dynamically added or removed just like physical I/O slots.

• Cannot be dynamically moved to another partition

Integrated Virtual Ethernet

• Also referred to as host Ethernet adapter:

• Included in many POWER6 and POWER7 system configurations.

• Provides network connectivity for LPARs without a Virtual I/O Server:

• Integrated high-speed Ethernet ports with hardware-assisted virtualization capabilities.

• Offers virtualization support for Ethernet connections.

• Depending on the system model, multiple types are available:

• Two port 1 Gba

• Four port 1 Gba

• Two port 10 Gbb

• Two 10 Gbb and two 1 Gb portsa

• Connected to the GX+ bus:

• An LHEA must be created on the logical partition.

Active Memory Sharing

• Active Memory Sharing (AMS) allows multiple LPARs to share a common pool of physical memory.

• AMS intelligently assigns memory from one partition to another based on memory page demands.

• Optimizes memory utilization and provides flexible memory usage

Active Memory Deduplication

Active Memory Expansion

• Compresses in-memory data to fit more data into memory:

• The physical memory requirements of existing LPARs is reduced.

• Free memory capacity can be used to create more LPARs.

• Increases a LPAR’s effective memory capacity:

• Can increase the effective memory capacity of a LPAR.

• Increases the memory available to a workload.

Live Partition Mobility

• Migration or movement of an LPAR from one physical server to another.

• Useful for:

• Reducing the impact of planned outages and increasing application availability.

• Workload balancing and consolidation.

• Relocation of workload to enable workload.

• Provision of new technology with no disruption to service (migration to newer systems).

• Requirements:

• –POWER6 or POWER7 systems.

• –LPAR must only have virtual adapters.

Shared storage pools
Shared storage pools:
Provide distributed access to storage resources using a cluster. Shared storage pools use files called logical units as backup devices for virtualized storage devices.
Benefits:
•Simplify the aggregation of large numbers of disks across multiple Virtual I/O Servers.
•Improve the utilization of the available storage.
•Simplify administration tasks.