Introducing Xen Server

Introducing XenServerStephen Rice (Lead Software Engineer)June 2010

• What is server virtualization?

• What benefits does it have?

• Citrix XenServer in detail

• Taking a look at the feature list

Agenda

Server virtualization enables multiple virtual machines to run

on a single physical server.

Almost any operating system you want.Q. What can you run as a virtual machine?

• Windows (XP, Vista, 7, 2000, 2003, 2008…)

• Linux (RHEL, SLES, Debian, Centos, Oracle…)

• Many more community supported guests

• CPU, Memory

• Disks (storage)

• Networks

What does a virtual machine need?

Pool

Shared Storage

Non Virtual

zzz

zzz

Virtualization

• Server consolidation

• Failure recovery

• Security and sandboxing

• Resource balancing

• Backup, restore and clone

• Simple management

Benefits of Virtualization

• Server consolidation

Benefits of Virtualization

• Server power consumption

• Server cooling costs

• Space requirements

• Hardware maintenance costs

• Failure recovery

Benefits of Virtualization

• High availability

• Snapshot and restore

• Security and sandboxing

Benefits of Virtualization

• Malicious code

• Legacy testing

• Upgrade preview

• Resource balancing

Benefits of Virtualization

• Consolidate in periods of low demand

• Spread out for periods of high demand

• Monitor and adapt to changing requirements

• Backup, restore and clone

Benefits of Virtualization

• Rapid deployment of new setups

• Extend existing capabilities

• Simplify staging to production transition

• Simple management

Benefits of Virtualization

• Manage workloads from a single console

• Organizational tools

• At a glance status reports

• Server consolidation

• Failure recovery

• Security and sandboxing

• Resource balancing

• Backup, restore and clone

• Simple management

Benefits of Virtualization

Citrix XenServer in detail

Single operating system that has direct access to the underlying hardware.

Normal Server

Host OS has access to the hardware and runs a hypervisor which manages the VMs.

• E.g. VMWare Server

• Security and performance trade off

Type 2 Hypervisor

Hypervisor controls access to the hardware for all guests VMs.

• E.g. XenServer, VMWare ESXi

• ‘Bare metal’ performance

Type 1 Hypervisor

Hardware Hardware

OS Hypervisor

Hardware

Hypervisor

Citrix XenServer in detail

• Open source Xen / Open source XenServer

• Privileged VM called Domain 0

• Gives commands to the hypervisor

• Coordinates networking/storage

• Communicates with external clients

• XenCenter, Workload Balancing Server, Active Directory e.t.c

Citrix XenServer compared to Vmware ESXi

• Established server virtualization company

• Extra server to manage database (Single POF)

• Binary translation performance cost

• Mature feature list

• High cost

ESXi

vCenter

ESXi ESXi

Citrix XenServer compared to Vmware ESXi

• Each server keeps a copy of the database

• Any server elected as master

• Free, pay only for enterprise features

• Free, stateless thin management client

XenServer

XenServer

XenServer

Master

• Graphical interface

• VM console access

• Component integration

• Plugins and SDKs

XenCenter management console

• XML-RPC based

• Libraries and examples for Java, C#, C, Python, PowerShell

• XenCenter uses C# bindings

• http://community.citrix.com/display/xs/Download+SDKs

• Open source licensing

• Backwards compatible

Software development kit for XenServer

• 24 hour project using C# XenServer bindings

• Ask the VMs politely to turn off

• Knock them out if they don’t

• Turn off all slaves first before the master

• Allow the user to set which VMs should wake

SleepyLabs example

Message board

example

Hello world example

What else might you need?

• Safety while you sleep

• Automatically migrates VMs

• Guarantees protection

• Master failover

High availability

• Specify a memory range for VMs

• Squeezes and inflates memory

• Overcommit to run more VMs

Dynamic memory control

• Monitors VM resource use

• Recommends VM migrations

• Maximum performance

• Maximum density

• Automatic or manual

Workload balancing

• Integrates with active directory

• Specify a role per user

• Roles restrict users feature access

Role based access control

• Snapshot disks and memory

• Revert to any point in tree

• Running VM

Snapshot and revert

Summary

•Save money: power, space, maintenance cost•Simple management: XenCenter•Live migration: resource management, maintenance•Easy deployment: templates, cloning•Develop: SDK, open source

Free!•High availability for VMs during server failures•Dynamic memory control•Performance alerts with long term reporting

$1k / XenServer

•Workload balancing•Role based access control•Live memory snapshots•More...

$2.5k / XenServer

Citrix Tshirts, come see me afterwards

Also free...

stephen.rice@eu.citrix.com