xen server 6.2 technical sales presentation

XenServer 6.2 Technical OverviewJune 2013

What is XenServer?

© 2013 Citrix | Confidential – Do Not Distribute

What’s so Great About Xen?

• It’s robustᵒ Native 64-bit hypervisorᵒ Runs on bare metalᵒ Directly leverages CPU hardware for virtualization

• It’s widely-deployedᵒ Hundreds of thousands of organizations have deployed Xen

• It’s advancedᵒ Optimized for hardware-assisted virtualization and paravirtualization

• It’s trustedᵒ Open, resilient Xen security framework

• It’s part of mainline Linux

• Xen Project is a widely supported Linux Foundation collaborative effort


Understanding Architectural Components

The Xen Project hypervisor and control domain (dom0) manage physical server resources among virtual machines


Understanding the Domain 0 Component

Domain 0 is a compact specialized Linux VM that manages the network and storage I/O of all guest VMs … and isn’t the XenServer hypervisor


Understanding the Linux VM Component

Linux VMs include paravirtualized kernels and drivers, and Xen is part of Mainline Linux 3.0


Understanding the Windows VM Component

Windows VMs use paravirtualized drivers to access storage and network resources through Domain 0


XenServer Meets All Virtualization Needs

EnterpriseData Center

•High performance, resilient virtualization platform•Simple deployment and management model

DesktopVirtualization

•Optimized for high performance desktop workloads•Storage optimizations to control VDI CAPEX

•Scalable platform for IaaS and Cloud Service Providers•Powers the NetScaler SDX platform

Enterprise Data Center VirtualizationScalable virtualization platform


XenCenter – Simple XenServer Management

• Single pane of management glass

• Manage XenServer hostsᵒ Start/Stop VMs

• Manage XenServer resource poolsᵒ Shared storage

ᵒ Shared networking

• Configure advanced featuresᵒ HA, Reporting, Alerting

• Manage updates


Management Architecture Comparison

“The Other Guys”

Traditional ManagementArchitecture

Single backend management server

Citrix XenServer

DistributedManagement Architecture

Clustered management layer


Role-Based Administration

• Provide user roles with varying permissions

• Pool Admin• Pool Operator• VM Power Admin• VM Admin• VM Operator• Read-only

• Roles are defined within a Resource Pool

• Assigned to Active Directory users, groups

• Audit logging via Workload Reports


XenMotion Live VM Migration

XenServerXenServerXenServer

Shared StorageMore about XenMotion


XenServer Pool

• Migrates VM disks from any storage type to any other storage typeᵒ Local, DAS, iSCSI, FC

• Supports cross pool migrationᵒ Requires compatible CPUs

• Encrypted Migration model

• Specify management interface for optimal performance

Live Storage XenMotion

XenServer Hypervisor

VDI(s)

Live Virtual

Machine

More about Storage XenMotion


Heterogeneous Resource Pools

Safe Live Migrations

Feature 5

Virtual Machine

Older CPU

Feature 1

Feature 2

Feature 3

Feature 4

XenServer 1

Newer CPU

Feature 1

Feature 2

Feature 3

Feature 4

XenServer 2

Mixed Processor Pools


Memory Overcommit

• Feature name: Dynamic Memory Control

• Ability to over-commit RAM resources

• VMs operate in a compressed or balanced mode within set range

• Allow memory settings to be adjusted while VM is running

• Can increase number of VMs per host


Virtual Appliances (vApp)

• Support for “vApps” or Virtual Appliancesᵒ OVF definition of Virtual Appliance

• vApp contains one or more Virtual Machines

• Enables grouping of VMs which can be utilized byᵒ XenCenterᵒ Integrated Site Recoveryᵒ Appliance Import and Exportᵒ HA


High Availability in XenServer

• Automatically monitors hosts and VMs

• Easily configured within XenCenter

• Relies on Shared Storageᵒ iSCSI, NFS, HBA

• Reports failure capacity for DR planning purposes

More about HA

Advanced Data Center Automation


Virtualization can hinder the linkage

between servers and storage, turning

expensive storage systems into little

more than “dumb disks”

XenServer Hosts

StorageVirtual Servers StorageLink

Citrix StorageLink™ technology lets your

virtual servers fully leverage all the

power of existing storage systems

XenServer Hosts

Optimizing Storage – Integrated StorageLink

More about StorageLink


Integrated Site Recovery

• Supports LVM SRs

• Replication/mirroring setup outside scope of solutionᵒ Follow vendor instructionsᵒ Breaking of replication/mirror also manual

• Works with every iSCSI and FC array on HCL

• Supports active-active DR

More about Site Recovery


Live Memory Snapshot and Rollback

• Live VM snapshot and revertᵒ Both memory and disk state are

capturedᵒ Optional quiesce option via VSS

provider (Windows guests)ᵒ One-click revert

• Snapshot branchesᵒ Support for parallel subsequent

checkpoints based on a previous common snapshot

Desktop Optimized XenServer


Supporting High Performance Graphics

• Feature name: GPU pass-through

• Enables high-end graphics in VDI deployments with HDX 3D Pro

• Optimal CAD application support with XenDesktop

• More powerful than RemoteFX, virtual GPUs, or other general purpose graphics solutions


Benefits of GPU Pass-through

With GPU pass-through, hardware costs are cut up to 75%

GPU cards

XenServer Host

Without GPU pass-through, each user requires their own Blade PC

More about GPU Pass Through


Controlling Shared Storage Costs – IntelliCache

• Caching of XenDesktop images

• Leverages local storage

• Reduce IOPS on shared storage


IntelliCache Fundamentals1. Master Image created through

XenDesktop MCS

2. VM is configured to use Master Image

3. VM using Master Image is started

4. XenServer creates read cache object on local storage

5. Reads in VM being done from local cache

6. Additional Reads done from SAN when required

7. Writes will happen in VHD child per VM

8. Local “write” cache is deleted when VM is shutdown/restarted

9. Additional VMs will use same read cache

XenDesktop

NFS Based Storage

VMVM

VMXenServer

Master ImageCache0011010100110101

011001

00110101


Cost Effective VM Densities

• Supporting VMs with up to:ᵒ 16 vCPU per VMᵒ 128GB Memory per VM

• Supporting XenServer hosts with up to:ᵒ 1TB Physical RAMᵒ 160 logical processors

• Yielding up to 225 Desktop images per host (LoginVSI Medium)

• Included at no cost with all XenDesktop purchases

• Cisco Validated Design for XenDesktop on UCS

Cloud Optimized XenServer


Distributed Virtual Network Switching

• Virtual Switchᵒ Open source: www.openvswitch.orgᵒ Provides a rich layer 2 feature setᵒ Cross host internal networksᵒ Rich traffic monitoring optionsᵒ ovs 1.4 compliant

• DVS Controllerᵒ Virtual applianceᵒ Web-based GUIᵒ Can manage multiple poolsᵒ Can exist within pool it managesᵒ Note: Controller is deprecated, but supported

VM

VM

VM

VM

VM

http://www.openvswitch.org/


Switch Policies and Live Migration

VM

VM

VM

VM

Linux VM1• Allow all traffic

Linux VM2• Allow SSH on eth0• Allow HTTP on eth1

Windows VM• Allow RDP and deny HTTP

Linux VM1• Allow all traffic

Linux VM2• Allow SSH on eth0• Allow HTTP on eth1

Windows VM• Allow RDP and deny HTTP

SAP VM• Allow only SAP traffic• RSPAN to VLAN 26

Windows VM• Allow all traffic

Linux VM• Allow SSH on eth0• Allow HTTP on eth1

Windows VM• Allow all traffic

SAP VM• Allow only SAP traffic• RSPAN to VLAN 26

Linux VM• Allow SSH on eth0• Allow HTTP on eth1

VM

More about DVSC


Single Root IO Virtualization (SR-IOV)

• PCI Specification for direct IO accessᵒ Hardware supports multiple PCI ids ᵒ Presents multiple virtual NICs from single NIC

• Virtual NICs presented directly into guestsᵒ Minimize hypervisor overhead in high

performance networks

• Not without downsidesᵒ Requires specialized hardwareᵒ Can not participate in DVSᵒ Does not support live migrationᵒ Limited number of virtual NICs

GuestVM

NIC

dom0

Physical driver

App

VF driver

vSwitch

GuestVMApp

VF driver

Virtual NIC Virtual NIC

More about SRIOV


NetScaler SDX – Powered by XenServer

• Complete tenant isolation

• Complete independence

• Partitions within instances

• Supportsᵒ NetScaler VPX and Branch Repeaterᵒ Windows 2008 R2ᵒ Virtualized Storefrontᵒ Virtualized Sharefile

• Optimized network: 120+ Gbps

• Runs default XenServer 6

XenServer Editions


Core Feature MatrixFeature XenServer 6.2

64-bit Xen Hypervisor a

Active Directory Integration a

Role-Based Administration and Audit Trail a

VMware to XenServer Conversion Utilities a

Multi-Server Management with XenCenter a

Live VM Migration with XenMotion™ a

Live Storage Migration with Storage XenMotion™ a

Dynamic Memory Control a

Host Failure Protection with High Availability a

Performance Reporting and Alerting a

Mixed Resource Pools with CPU Masking a

GPU Pass-Through for Desktop Graphics Processing a

IntelliCache™ for XenDesktop Storage Optimization a

Live Memory Virtual Machine Snapshot and Revert a

OpenFlow Distributed Virtual Switch a

Integrated Multi-site Recovery a

Added Operating Systems: Windows 8, Windows Server 2012, Debian Wheezy, *EL 6.3/6.4

Supported Virtual Machine Density 225 Windows 8 LoginVSI Medium/500 General purpose

Price Free


Simple Packaging and Pricing

Commercially packaged and certified distribution of XenServer that includes*:• Product License• XenServer Maintenance*

• Premier Support• Subscription Advantage

• Ability to use XenCenter for updates

Perpetual$1,250

/socket*Annual

$500/socket*

Citrix XenServer

Free, open source distribution of XenServer.• Citrix Technical Support not available• Access limited to major updates only• Command line updates/patches

FREEOpen Source XenServer

New

*Citrix XenServer is sold in conjunction with 1-year of XenServer Maintenance


NewPricing

Citrix XenServer 6.2 PriceAnnual

XenServer License – 1 year (per socket) $400XenServer License – 3 year (per socket) $1050XenServer Maintenance (SA + Support) – 1 year (per socket)* $100XenServer Maintenance (SA + Support) – 3 year (per socket)* $300

PerpetualXenServer License (per socket) $1025XenServer Maintenance (SA + Support) – 1 year (per socket)* $225

*Citrix XenServer is sold in conjunction with 1-year of XenServer Maintenance*XenServer Maintenance is required when purchasing Citrix XenServer


XenServer Annual Promo

• Encourage first time users or existing Free and OSS users to get the commercial version of XenServer with aggressively priced annual license option.

• 1yr. annual XenServer 6.2 license term only

• Available July 25, 2013 through Dec 31, 2013

• All standard discount programs apply

• Promo pricing available in the Online Store

XenServer License Types XenServer 6.2

Annual XenServer License – 1 year (per socket)* *Maintenance is required $99

XenServer Software Maintenance Annual (SA + Support) 1 year (per socket) $100

Total $199

New


Additional Support Options XenServer Support Options Premier SupportCost Included with Software MaintenanceCoverage Hours 24x7x365Incidents UnlimitedNamed Contacts UnlimitedType of Access Phone/Web/Email

Add-on Service OptionsSoftware or Hardware TRM 200 hours/Unlimited incidents/1region $40,000

Additional TRM hours 100 hours $20,000

Fully Dedicated TRM 1600 hours/Unlimited incidents/1 region $325,000

On-site Days On-site technical support service $2,000 per day

Assigned Escalation 200 hours/1 region (must have TRM) $16,000

Fully Dedicated Assigned Escalation 1600 hours $480,000


It’s Your Budget … Spend it Wisely

• Vendor lock-in great for vendor• Beware product lifecycles and tool set changesSingle Vendor

• ROI Calculators always show vendor author as best• Use your own numbersROI Can be Manipulated

• Over buying is costly; get what you need• Support call priority with tiered modelsUnderstand Support Model

• Some projects have requirements best suited to specific tool• Understand deployment and licensing impactUse Correct Tool

• Blanket purchases benefit only vendor• Chargeback to project for feature requirements

Leverage Costly Features as Required

Work better. Live better.

GPU Pass-through Details


How GPU Pass-through Works

• Identical GPUs in a host auto-create a GPU group

• The GPU Group can be assigned to set of VMs – each VM will attach to a GPU at VM boottime

• When all GPUs in a group are in use, additional VMs requiring GPUs will not start

• GPU and non-GPU VMs can (and should) be mixed on a host

• GPU groups are recognized within a poolᵒ If Server 1, 2, 3 each have GPU type 1, then

VMs requiring GPU type 1 can be started on any of those servers


GPU Pass-through HCL is Server Specific

• Serverᵒ HP ProLiant WS460c G8 Workstation series*ᵒ IBM System x3650 M3, dx360ᵒ Dell Precision R5500, R720ᵒ Cisco UCS C240 M3

• GPU (1-4 per host)ᵒ NVIDIA Quadro 2000, 4000, 5000, 6000ᵒ NVIDIA Tesla M2070-Q ᵒ NVIDIA GRID K1 and K2ᵒ AMD FirePro S7000, S9000

• Support for Windows guests only

• Important: Combinations of servers + GPUs must be tested as a pair


Limitations of GPU Pass-through

• GPU Pass-through binds the VM to host for duration of session ᵒ Restricts XenMotion

• Multiple GPU types can exist in a single serverᵒ E.g. high performance and mid performance GPUs

• VNC will be disabled, so RDP is required

• Fully supported for XenDesktop, best effort for other windows workloads ᵒ Not supported for Linux guests

• HCL is very important

IntelliCache Details


Enabling IntelliCache on XenServer Hosts

• IntelliCache requires local EXT3 storage, to be selected during XenServer installation

• If this is selected during installation the host is automatically enabled for IntelliCache

• Manual steps in Admin guide


Enabling IntelliCache in XenDesktop

• http://support.citrix.com/article/CTX129052

• Use IntelliCache checkbox when adding a host in Desktop Studio

• Supported from XenDesktop 5 FP1

http://support.citrix.com/article/CTX129052




IOPS – 1000 Users – No IntelliCache

0:00:000:01:500:03:400:05:300:07:200:09:100:11:000:12:500:14:400:16:300:18:200:20:100:22:000:23:500:25:400:27:300:29:200:31:100:33:000:34:500:36:400:38:300:40:200:42:100:44:000

2000

4000

6000

8000

10000

12000

14000

16000

18000

NFS Ops (Non-IC)

NFS Read Ops NFS Write Ops

NFS

Ops


IOPS – 1000 Users – Cold Cache Boot

0:00:000:01:400:03:200:05:000:06:400:08:200:10:000:11:400:13:200:15:000:16:400:18:200:20:000:21:400:23:200:25:000:26:400:28:200:30:000:31:400:33:200:35:000:36:400:38:200:40:000:41:400

500

1000

1500

2000

2500

3000

NFS Ops (Cold Cache)


NFS

Ops


IOPS – 1000 Users – Hot Cache Boot

0:00:00 0:01:50 0:03:40 0:05:30 0:07:20 0:09:10 0:11:00 0:12:50 0:14:40 0:16:30 0:18:20 0:20:10 0:22:00 0:23:50 0:25:40 0:27:30 0:29:20 0:31:10 0:33:00 0:34:50 0:36:40 0:38:30 0:40:20 0:42:10 0:44:000

5

10

15

20

25

30

35

NFS Ops (Hot Cache)


NFS

Ops


Limitations of IntelliCache

• Best results achieved with local SSD drivesᵒ SAS and SATA supported, but spindled disks are slower

• XenMotion with pooled images

• Best practice Local space sizingᵒ Expecting 50% cache usage per user + daily log offᵒ [real size master image] + #[users per server] * [size master image] * 0,5ᵒ Cache disk may vary according to VM lifecycle definition (reboot cycle)


IntelliCache Conclusions

• Dramatic reduction of I/O for pooled desktops

• Significant reduction of I/O for assigned desktopsᵒ Still need IOPS for write trafficᵒ Local write cache benefits

• Storage investment much lower – and more appropriate

• Overall TCO 15 – 30 % improvement

• Continued evolution of features to yield better performance and TCO

Integrated Site Recovery Details


Integrated Site Recovery

• Supports LVM SRs only

• Replication/mirroring setup outside scope of solutionᵒ Follow vendor instructionsᵒ Breaking of replication/mirror also manual

• Works with every iSCSI and FC array on HCL

• Supports active-active DR


Feature Set

• Integrated in XenServer and XenCenter

• Support failover and failback

• Supports grouping and startup order through vApp functionality

• Failover pre-checksᵒ Powerstate of source VMᵒ Duplicate VMs on target poolᵒ SR connectivity

• Ability to start VMs paused (e.g. for dry-run)


How it Works

• Depends on “Portable SR” technologyᵒ Different from Metadata backup/restore functionality

• Creates a logical volume on SR during setup

• Logical Volume containsᵒ SR metadata informationᵒ VDI metadata information for all VDIs stored on SR

• Metadata information is read during failover sr-probe


Integrated Site Recovery - Screenshots

Deprecated

Note: Aspects of the functionality contained in this section have been deprecated. This means you are fully supported if you deploy using this version, but no new features or functionality will be developed.

Distributed Virtual Switch DetailsOnly the Virtual Switch Controller is deprecated


Terminology

• OpenFlowᵒ An open standard that separates the control and data paths for switching devices

• OpenFlow switchᵒ Could be physical or virtualᵒ Includes packet processing and remote configuration/control support via OpenFlow

• Open vSwitchᵒ An OSS Linux-based implementation of an OpenFlow virtual switchᵒ Maintained at www.openvswitch.org

• vSwitch Controllerᵒ A commercial implementation of a OpenFlow controllerᵒ Provides integration with XenServer poolsᵒ Note: Controller functionality has been deprecated, but remains supported

http://www.openvswitch.org/


Core Distributed Switch Objectives

• Extend network management to virtual networks

• Provide network monitoring using standard protocols

• Define network policies on virtual objects

• Support multi-tenant virtual data centers

• Provide cross host private networking without VLANs

• Answer to VMware VDS and Cisco Nexus 1000v


Understanding Policies

• Access controlᵒ Basic Layer 3 firewall rulesᵒ Definable by pool/network/VMᵒ Inheritance controls VM

VM

VM

VM

VM



• Access control

• QoSᵒ Rate limits to control bandwidth

VM

VM

VM

VM

VM



• Access control

• QoS

• RSPANᵒ Transparent monitoring of VM level

traffic

VM

VM

VM

VM


What is NetFlow?

• Layer 3 monitoring protocol

• UDP/SCTP based

• Broadly adopted solution

• Implemented in three partsᵒ Exporter (DVS)ᵒ Collectorᵒ Analyzer

• DVSC is NetFlow v5 basedᵒ Enabled at pool level


Performance Monitoring

• Enabled via NetFlow

• Dashboardᵒ Throughputᵒ Packet flowᵒ Connection flow

• Flow Statisticsᵒ Slice and dice reportsᵒ See top VM trafficᵒ Data goes back 1 week


Bonus Features

• Jumbo Frames

• Cross Server Private Networks

• LACP

• 4 NIC bonds

High Availability Details


Protecting Workloads

• Not just for mission critical applications anymore

• Helps manage VM density issues

• "Virtual" definition of HA a little different than physical

• Low cost / complexity option to restart machines in case of failure


High Availability Operation

• Pool-wide settings

• Failure capacity – number of hosts to carry out HA Plan

• Uses network and storage heartbeat to verify servers


VM Protection Options

• Restart Priorityᵒ Do not restartᵒ Restart if possibleᵒ Restart

• Start Orderᵒ Defines a sequence and delay to ensure applications run correctly


HA Design – Hot Spares

Simple Designᵒ Similar to hot spare in disk arrayᵒ Guaranteed availableᵒ Inefficient Idle resources

Failure Planningᵒ If surviving hosts are fully loaded – VMs will be forced to start on spareᵒ Could lead to restart delays due to resource plugsᵒ Could lead to performance issues if spare is pool master


HA Design – Distributed Capacity

Efficient Designᵒ All hosts utilized

Failure Planningᵒ Impacted VMs automatically placed for best fitᵒ Running VMs undisturbedᵒ Provides efficient guaranteed availability


HA Design – Impact of Dynamic Memory

Enhances Failure Planningᵒ Define reduced memory which meets SLAᵒ On restart, some VMs may “squeeze” their memoryᵒ Increases host efficiency


HA Enhancements in XenServer 6

• HA over NFS

• HA with Application Packagesᵒ Define multi-VM servicesᵒ Define VM startup order and delaysᵒ Application packages can be defined from

running VMs

• Auto-Start VMs are removedᵒ Usage conflicted with HA failure planningᵒ Created situations when perceived host

recovery wasn’t met


High Availability – No Excuses

• Shared storage the hardest part of setupᵒ Simple wizard can have HA defined in minutesᵒ Minimally invasive technology

• Protects your important workloadsᵒ Reduce on-call support incidentsᵒ Addresses VM density risksᵒ No performance, workload, configuration penalties

• Compatible with resilient application designs

• Fault tolerant options exist through ecosystem

Deprecated

Note: Aspects of the functionality contained in this section have been deprecated. This means you are fully supported if you deploy using this version, but no new features or functionality will be developed.

StorageLink Details


Array OS

SnapshottingProvisioning

Cloning

Leverage Array Technologies

• No file system overlay

• Use Best-of-Breed technologiesᵒ Thin Provisioningᵒ Deduplexingᵒ Cloningᵒ Snapshottingᵒ Mirroring

• Maximize array performance

Hypervisor Filesystem


Cloning

VM VM VM VM VM

VM VM VM VM VM

Array OS


Cloning

VM VM VM VM VM

VM VM VM VM VM

Traditional Approach Citrix StorageLink


LUN 600GB

LUN 600GBLUN 600GB

No StorageLink – Inefficient LUN Usage

1 TB storage capacity

Today

Customer request for 600GB

LUN 600GB

4 weeks

Customer adds 5 VMswith 50 GB each

8 weeks


12 weeks


Customer requests new

storage capacity

400 GB free

50GB disk50GB disk

50GB disk50GB disk50GB disk

50GB disk50GB disk


50GB disk50GB disk


50GB disk50GB disk


400 GB free

50GB disk50GB disk


400 GB free

LUN 600GB


With StorageLink – Maximize Array Utilization

1 TB storage capacity

Today

Customer request for 600 GB

4 weeks


8 weeks


500 GB free

12 weeks


50GB LUN50GB LUN

50GB LUN50GB LUN50GB LUN

50GB LUN50GB LUN


50GB LUN50GB LUN


50GB LUN50GB LUN


50GB LUN50GB LUN


750 GB free

50GB LUN50GB LUN


1 TB free 250 GB free


StorageLink – Efficient Snapshot Management

LUN 600GB

400 GB free

50GB disk50GB disk


NO StorageLink

VM Snapshot capacity limited to LUN size

Snapshot capacity

50GB LUN50GB LUN


With StorageLink

VM Snapshot capacity limited storage pool size

750 GB350 GB

750 GB free


Integrated StorageLink Architecture

XenServer Host

XAPI Daemon

SMAPI

LVM NFS NetApp CSLGBridge

…

EQL NTAP SMI-S …

SR-IOV Details


Network Performance for GbE with PV drivers

• XenServer PV drivers can sustain peak throughput on GbEᵒ However limited to 2.9Gb/s in total

• But XenServer uses significantly more CPU cycles than Linuxᵒ Less available cycles for applicationᵒ 10GbE networks: CPU saturation in dom0 prevents achieving line rate

• Need to reduce I/O virtualization overhead in XenServer networking


I/O Virtualization Overview – Hardware Solution

• VMDq (Virtual Machine Device Queue)ᵒ Separate Rx & Tx queue pairs of NIC for

each VM, Software “switch”.

• Direct I/O (VT-d)ᵒ Improved I/O performance through direct

assignment of a I/O device to a HVM or PV workload

• SR-IOV (Single Root I/O Virtualization)ᵒ Changes to I/O device silicon to support

multiple PCI device ID’s, thus one I/O device can support multiple direct assigned guests. Requires VT-d.

Network Only

VM exclusivelyowns device

One Device, multiple Virtual Functions


Where Does SR-IOV Fit In?

Technique \ Characteristic

Efficiency Hardware Abstraction Applicability Scalability

Emulation Low Very high All device classes High

Para-virtualization Medium High – requires installing paravirtual drivers on the guest

Block, network High

Acceleration (VMDq) High Medium:-Transparent to apps-May require device-specific accelerators

Network only, hypervisor dependent

Medium (for accelerated interfaces)

PCI Pass-through High Low:-Explicit device plug/unplug-Device specific drivers

All devices Low

SR-IOV Addresses This


XenServer Solarflare SR-IOV Implementation

GuestVM

NIC

dom0

Physical driver

App

VF driver

vSwitch

GuestVMApp

VF driver

Virtual NIC Virtual NIC

Improved performance, but loss of services and management (e.g. live migration)

GuestVM

NIC

dom0

Physical driver

App

Plug-in driverNetfront

driver

Netback driver

vSwitch

Virtual NIC

VF

Improved performance AND full use of services and management

XS & Solarflare SR-IOV ModelTypical SR-IOV Implementation

Experimental

XenMotion in Detail


XenMotion – Live VM Migration

• Requires systems that have compatible CPUsᵒ Must be the same manufacturerᵒ Can be different speedᵒ Must support maskable features; or be of simlar type (e.g. 3450 and 3430)

• Minimal Downtimeᵒ Generally sub 200 mS; mostly due to network switches

• Requires shared storageᵒ VM state moves between hosts; underlying disks remain in existing location

Detailed XenMotion Example


• Systems verify correct storage and network setup on destination server• VM Resources Reserved on Destination Server

Pre-Copy Migration: Round 1

Source Virtual Machine Destination


Pre-Copy Migration: Round 1• While source VM is still running XenServer copies over memory image to destination server• XenServer keeps track of any memory changes during this process


• After first pass most of the memory image is now copied to the destination server• Any memory changes during initial memory copy are tracked



• XenServer now does another pass at copying over changed memory



• Xen still tracks any changes during the second memory copy• Second copy moves much less data• Also less time for memory changes to occur



• Xen will keep doing successive memory copies until minimal differences between source and destination

Pre-Copy Migration


• Source VM is paused and last bit of memory and machine state copied over• Master unlocks storage from source system and locks to destination system• Destination VM is unpaused and attached to storage and network resources• Source VM resources cleared

XenMotion: Final

Storage XenMotion


XenServer Pool

Live Storage XenMotionUpgrading VMs from Local to Shared Storage


Local Storage

FC, iSCSI, NFS SAN

VDI(s)VDI(s)

Live Virtual

Machine


XenServer Pool

Live Storage XenMotionMoving VMs within a Pool with local-only storage


Local Storage


Local Storage

Live Virtual

Machine

VDI(s)VDI(s)


XenServer Pool 2XenServer Pool 1

Live Storage XenMotionMoving or rebalancing VMs between Pools (Local SAN)

Local Storage

XenServer HypervisorXenServer HypervisorXenServer HypervisorXenServer HypervisorXenServer HypervisorXenServer Hypervisor

VDI(s)

FC, iSCSI, NFS SAN

VDI(s)

Live Virtual

Machine


XenServer Pool 2XenServer Pool 1

Live Storage XenMotionMoving or rebalancing VMs between Pools (Local Local)

Local Storage

XenServer HypervisorXenServer HypervisorXenServer Hypervisor

Local Storage

XenServer HypervisorXenServer HypervisorXenServer Hypervisor

Live Virtual

Machine

VDI(s)VDI(s)


VHD Benefits

• Many SRs implement VDIs as VHD trees

• VHDs are a copy-on-write format for storing virtual disks

• VDIs are the leaves of VHD trees

• Interesting VDI operation: snapshot (implemented as VHD “cloning”)

• A: Original VDI

• B: Snapshot VDI

A

RW

BRO

ARW

RO


VDI Mirroring FlowSOURCE DESTINATION

mirror

copy

root

VM VM

no color = emptygradient = live


Benefits of VDI Mirroring

• Optimization: start with most similar VDIᵒ Another VDI with the least number of different blocksᵒ Only transfer blocks that are different

• New VDI field: Content ID for each VDIᵒ Easy way to confirm that different VDIs have identical contentᵒ Preserved across VDI copy, refreshed after VDI attached RW

• Worst case is a full copy (common in server virtualization)

• Best case occurs when you use VM “gold images” (i.e. XenDesktop)

Work better. Live better.

xen server 6.2 technical sales presentation

Technology

citrix confidential

xenserver pool

linux vm component linux

management interface

storage io

vm disks

xenserver resource pools

storage shared networking