virtualisation overview

© Copyright IBM Corporation 20093.2

PowerVM Virtualization plain and simple

© Copyright IBM Corporation 2009

IBM System p

Goals with Virtualization

Lower costs and improve resource utilization- Data Center floor space reduction or…- Increase processing capacity in the same space- Environmental (cooling and energy challenges)- Consolidation of servers- Lower over all solution costs

Less hardware, fewer software licenses

- Increase business flexibility Meet ever changing business needs faster provisioning

- Improving Application Availability Flexibility in moving applications between servers


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The virtualization elevator pitch

• The basic elements of PowerVM- Micro-partitioning – allows 1 CPU look like 10- Dynamic LPARs – moving resources- Virtual I/O server – partitions can share

physical adapters- Live partition mobility – using Power6- Live application mobility – using AIX 6.1


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First there were servers

• One physical server for one operating system

• Additional physical servers added as business grows

Physical view Users view


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Then there were logical partitions

• One physical server was divided into logical partitions

• Each partition is assigned a whole number of physical CPUs (or cores)

• One physical server now looks like multiple individual servers to the user

Physical view

8 CPUs

Users viewLogical view

1 CPUs

3 CPUs

2 CPUs

2 CPUs


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Then came dynamic logical partitions

• Whole CPUs can be moved from one partition to another partition

• These CPUs can be added and removed from partitions without shutting the partition down

• Memory can also be dynamically added and removed from partitions

Physical view

8 CPUs


1 CPUs

3 CPUs

2 CPUs

2 CPUs

1 CPUs

3 CPUs

2 CPUs


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Dynamic LPAR

•Standard on all POWER5 and POWER6 systems

HMC

AIX 5L

Linux

Hypervisor

Part#1

Production

Part#2 Part#3 Part#4

Legacy Apps

Test/Dev

File/Print

AIX 5L

AIX 5L

Move resources between live

partitions


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Now there is micro partitioning

• A logical partition can now have a fraction of a full CPU

• Each physical CPU (core) can be spread across 10 logical partitions

• A physical CPU can be in a pool of CPUs that are shared by multiple logical partitions

• One physical server can now look like many more servers to the user

• Can also dynamically move CPU resources between logical partitions

Physical view

8 CPUs


0.2 CPU

2.3 CPUs

1.2 CPUs

1 CPU

0.3 CPU

1.5 CPUs

0.9 CPU


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Logical partitions (LPARs) can be defined with dedicated or shared processors

Processors not dedicated to a LPAR are part of the pool of shared processors

Processing capacity for a shared LPAR is specified in terms of processing units.

With as little as 1/10 of a processor

Micro-partitioning terminology


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Micro-partitioning – more details

Lets look deeper into micro-partitioning


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A physical CPU is a single “core” and also called a “processor”

The use of micro-partitioning introduces the virtual CPU conceptA virtual CPU could be a fraction of a physical CPUA virtual CPU can not be more than a full physical CPU

IBM’s simultaneous multi threading technology (SMT) enables two threads to run on the same processor at the same time.

With SMT enabled the operating system sees twice the number of processors

Micro-partitioning terminology (details)

Physical CPU

Virtual CPU

Virtual CPU

Virtual CPU

Logical CPU

Logical CPU

Logical CPU

Logical CPU

Logical CPU

Logical CPUUsing SMT

Using micro-partitioning

Each logical CPU appears to the

operating system as a full CPU


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The LPAR definition sets the options for processing capacity:ƒ Minimum:ƒ Desired:ƒ Maximum:

The processing capacity of an LPAR can be dynamically changedƒ Changed by the administrator at the HMCƒ Changed automatically by the hypervisor

The LPAR definition set the behavior when under a load ƒ Capped: LPAR processing capacity is limited to the desired setting

ƒ Uncapped: LPAR is allowed to use more then it was given

Micro-partitioning terminology (details)


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Shared processor pool

Basic terminology around Logical Partitions

Shared processor partitionSMT Off

Shared processor partitionSMT On

Dedicated processor partition

SMT Off

Deconfigured

Inactive (CUoD)

Dedicated

Shared

Virtual

Logical (SMT)

Installed physical processors

Entitled capacity


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Capped and uncapped partitions

• Capped partition- Not allowed to exceed its entitlement

• Uncapped partition- Is allowed to exceed its entitlement

• Capacity weight- Used for prioritizing uncapped partitions- Value 0-255- Value of 0 referred to as a “soft cap”

Note: The CPU utilization metric has less relevance in the uncapped partition.


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What about system I/O adapters

• Back in the “old” days, each partition had to have its own dedicated adapters

• One Ethernet adapter for a network connection

• One SCSI or HBA card to connect to local or external disk storage

• The number of partitions was limited by the number of available adapters

Physical

adapters Users view

Logical

Partitions

1 CPUs

3 CPUs

2 CPUs

2 CPUs

Ethernet adap

Ethernet adap

Ethernet adap

Ethernet adap

SCSI adap

SCSI adap

SCSI adap

SCSI adap


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Then came the Virtual I/O server (VIOS)

• The virtual I/O server allows partitions to share physical adapters

• One Ethernet adapter can not provide a network connection for multiple partitions

• Disks on one SCSI or HBA card can now be shared with multiple partitions

• The number of partitions is no longer limited by the number of available adapters

Ethernet adap

SCSI adap

Virtual I/O Server partition

0.5 CPU

1.1 CPUs

0.3 CPU

1.4 CPUs

2.1 CPUs

Ethernet network


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Virtual I/O server and SCSI disks


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Integrated Virtual Ethernet

LPAR#2

LPARVIOS

LPAR#3

LPAR#1

Power Hypervisor

SEA

Virtual Ethernet Switch

VirtualEthernet

Driver

VirtualEthernet

Driver

VirtualEthernet

Driver

LPAR#2

LPARVIOS

LPAR#3

LPAR#1

Power Hyper-visor

SEA EthernetDriver

EthernetDriver

EthernetDriver

IntegratedVirtual Adapter

VIOS Set up is not required for sharing Ethernet Adapters

PCI Ethernet Adapter

Virtual I/O Shared Ethernet Adapter Integrated Virtual Ethernet

vs


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Lets see it in action

Now let’s see this technology in action

This demo illustrates the topics just discussed


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Shared Processor pools

It is possible to have multiple shared processor pools

Lets dive in deeper


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Linux Software: A,B,C

AIX 5L Software: X,Y,Z

Multiple Shared Processor Pools

VSP2 Max Cap=2VSP1 Max Cap=4

AIX 5L DB/2

Physical Shared Pool

► Useful for multiple business units in a single company – resource allocation► Only license the relevant software based on VSP Max► Cap total capacity used by a group of partitions ► Still allow other partitions to consume capacity not used by the partitions

in the VSP


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AIX 6.1 Introduces Workload Partitions

• Workload partitions (WPAR) is yet another way to create virtual systems

• WPARs are partitions within a partition

• Each partition is isolated from one another

• AIX 6.1 can be run on Power5 or Power6 hardware


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AIX 6 Workload Partitions (details)

WPAR appears to be a stand alone AIX system

Created entirely within a single AIX system image

Created entirely in software (no HW assist or configuration)

Provides an isolated process environment: Processes within a WPAR can only see other processes in the same partition.

Provides an isolated file system space A separate branch of the global file system space is

created and all of the WPARS processes are chrooted to this branch.

Processes within a WPAR see files only in this branch.

Provides an isolated network environment Separate network addresses, hostnames, domain names Other nodes on the network see WPAR as a stand alone

system.

Provides WPAR resource controls The amount of system memory, CPU resources, paging

space allocated to each WPAR can be set.

Shared system resources: OS, I/O Devices, Shared Library

WorkloadPartition

A

WorkloadPartition

C

WorkloadPartition

B

AIX 6 Image

WorkloadPartition

DWorkloadPartition

E


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Inside a WPAR


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WorkloadPartition

Billing

WorkloadPartition

QA

AIX # 2

WorkloadPartition

Data Mining

Live Application Mobility

WorkloadPartition

ApplicationServer

WorkloadPartition

Web

AIX # 1

ApplicationPartition

Dev

The ability to move a Workload Partition from one server to another

Provides outage avoidance and multi-system workload balancing

Workload Partition

eMail

Policy based automation can provide more efficient resource usage

Workload

Partitions

Manager

Policy

NFS NFS


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Live application mobility in action

Lets see this techonolgy in action with another demo

Need to exit presentation in order to run the demo


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Power6 hardware introduced partition mobility

With Power6 hardware, partitions can not be moved from on system to another without stopping the applications running on that partition.


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Partition Mobility: Active and Inactive LPARs

Active Partition Mobility Active Partition Migration is the actual movement of a running LPAR from one

physical machine to another without disrupting* the operation of the OS and applications running in that LPAR.

Applicability Workload consolidation (e.g. many to one) Workload balancing (e.g. move to larger system) Planned CEC outages for maintenance/upgrades Impending CEC outages (e.g. hardware warning received)

Active Partition Mobility Active Partition Migration is the actual movement of a running LPAR from one

physical machine to another without disrupting* the operation of the OS and applications running in that LPAR.

Applicability Workload consolidation (e.g. many to one) Workload balancing (e.g. move to larger system) Planned CEC outages for maintenance/upgrades Impending CEC outages (e.g. hardware warning received)

Inactive Partition Mobility Inactive Partition Migration transfers a partition that is logically ‘powered off’ (not

running) from one system to another.

Inactive Partition Mobility Inactive Partition Migration transfers a partition that is logically ‘powered off’ (not

running) from one system to another.

Partition Mobility supported on POWER6AIX 5.3, AIX 6.1 and Linux


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Live partition mobility demo

The following demo show live partition mobility (LPM) in action


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Response Time & Utilization based Workload & Resource Management

AIX 5.3Linux

Partitions

Power Hypervisor

Virtual I/ O Server (VIOS)

Ethernet & Fiber Channel Adapter Sharing

Virtualized disks

Interpartition Communication

Dedicated I/O Shared I/O

AIX 6

IBM System p Offers Best of Both Worlds in Virtualization

WPARApplication

Server

WPARWeb

Server

WPARBilling

AIX instance

WPARTest

WPARBI

Logical Partitions (LPARS) AIX 6 Workload Partitions (WPARs)

Multiple OS Images in LPARs Up to a maximum of 254

Maximum Flexibility Different OSes and OS Versions in LPARs

Maximum Fault / Security / Resource Isolation

Multiple workloads within a single OS image Minimum number of OS Images: one

Improved administrative efficiency Reduce number of OS images to maintain

Good Fault / Security / Resource isolation

AIX Workload Partitions can be Used in LPARs


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Virtualization Benefits

• Increase Utilization- Single application servers

often run at lower average utilizations levels.

- Idle capacity cannot be used- Virtualized servers run at high

utilization levels.

• Simplify Workload Sizing- Sizing new workloads is difficult - LPARs can be resized to match needs- Can over commit capacity- Scale up and scale out applications on

the same hardware platform

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100

8:00 10:00 12:00 2:00 4:00

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Purchased

Peak

Average


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Backup slides

Still more details for those interest….


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Partition capacity entitlement

• Processing units- 1.0 processing unit represents one

physical processor• Entitled processor capacity

- Commitment of capacity that is reserved for the partition

- Set upper limit of processor utilization for capped partitions

- Each virtual processor must be granted at least 1/10 of a processing unit of entitlement

• Shared processor capacity is always delivered in terms of whole physical processors

Processing capacity1 physical processor1.0 processing units

0.5 processing unit 0.4 processing unit

Minimum requirement0.1 processing units


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Capped Shared Processor LPAR

Maximum Processor Capacity

Entitled Processor CapacityProcessorCapacityUtilization LPAR Capacity Utilization

Pool Idle Capacity Available

Time

minimum processor capacity

ceded capacity

utilized capacity


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Uncapped Shared Processor LPAR

Maximum Processor Capacity

ProcessorCapacityUtilization

Pool Idle Capacity Available

Time

Entitled Processor Capacity

minimum processor capacity

Utilized Capacity

ceded capacity


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Shared processor partitions

• Micro-Partitioning allows for multiple partitions to share one physical processor

• Up to 10 partitions per physical processor• Up to 254 partitions active at the same time• Partition’s resource definition

- Minimum, desired, and maximum values for each resource- Processor capacity- Virtual processors- Capped or uncapped

• Capacity weight

- Dedicated memory• Minimum of 128 MB and 16 MB increments

- Physical or virtual I/O resources

CPU 0 CPU 1

CPU 3 CPU 4

LPAR 1 LPAR 2

LPAR 5 LPAR 6

LPAR 4LPAR 3


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Understanding min/max/desired resource values

• The desired value for a resource is given to a partition if enough resource is available.

• If there is not enough resource to meet the desired value, then a lower amount is allocated.

• If there is not enough resource to meet the min value, the partition will not start.

• The maximum value is only used as an upper limit for dynamic partitioning operations.


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Partition capacity entitlement example

• Shared pool has 2.0 processing units available • LPARs activated in sequence• Partition 1 activated

- Min = 1.0, max = 2.0, desired = 1.5- Starts with 1.5 allocated processing units

• Partition 2 activated- Min = 1.0, max = 2.0, desired = 1.0- Does not start

• Partition 3 activated- Min = 0.1, max = 1.0, desired = 0.8- Starts with 0.5 allocated processing units


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Capped and uncapped partitions

• Capped partition- Not allowed to exceed its entitlement

• Uncapped partition- Is allowed to exceed its entitlement

• Capacity weight- Used for prioritizing uncapped partitions- Value 0-255- Value of 0 referred to as a “soft cap”


IBM System pShared Dedicated Capacity

0

25

50

75

100

125

150

175

200

1-way Dedicated Wasted Dedicated

0.5 Uncapped 1 0.5 Uncapped 2

Dedicated Processor Partitions often have excess capacity that can be utilized by uncapped micropartitions

Increased Resource Utilization

Today

Unused capacity in dedicated partitions gets wasted

0

25

50

75

100

125

150

175

200

1-way Dedicated Wasted Dedicated

0.5 Uncapped 1 0.5 Uncapped 2

With the new support, a dedicated partition will donate its excess cycles to the uncapped partitions

Results in increased resource utilization Dedicated processor partition maintains the performance

characteristics and predictability of the dedicated environment under load

With Shared Dedicated Capacity

Equivalent Workload Complete


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WPAR Manager view of WPARs


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Active Memory Sharing Overview

• Next step in resource virtualization, analogous to shared processor partitions that share the processor resources available in a pool of processors.

• Supports over-commitment of physical memory with overflow going to a paging device.- Users can define a partition with a logical memory size larger than the available physical

memory. - Users can activate a set of partitions whose aggregate logical memory size exceeds the

available physical memory.

• Enables fine-grained sharing of physical memory and automated expansion and contraction of a partition’s physical memory footprint based on workload demands.

• Supports OS collaborative memory management (ballooning) to reduce hypervisor paging.

A pool of physical memory is dynamically allocated amongst multiple logical partitions as needed to optimize overall physical memory usage in the pool.

virtualisation overview

Technology

copyright ibm corporation

physical cpu core

cpu resources

cpu look

ibm system p goals

number of physical cpus

virtual cpu concept

pool of cpus