Understanding Virtualization in Longhorn Server What

Understanding Virtualization in
Longhorn Server
Presented by Mark Minasi
help@minasi.com
Talk originally created by Michael Otey
Technical Director
Windows IT Pro Magazine
What this session covers
•
•
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Virtual machine basics
Virtualization scenarios
Virtualization with Virtual Server 2005 R2
Virtualization with Windows Server
Longhorn and the Hypervisor
• Managing VMs with upcoming tools
• FAQs about Windows Server Virtualization
Virtual Possibilities
• Create a set of uniform server builds, even on
dissimilar hardware
• Simplify disaster recovery
• Reduce hardware costs
• Reduce infrastructure costs
• Simplify testing
• Archive existing systems
• Virtual "appliances" and easily-implemented
demonstration software
Understanding Virtual
Machines
Basic Ideas
• Take an actual computer
• Build software to allow it to create
imaginary computers, "virtual machines"
• After creating a virtual machine, it acts like
a computer without an OS when booted
• Install software on it just as you would on
an actual machine
Virtual
Virtual Machine Virtualization
Applications
Applications
Guest OS
(Windows NT)
Guest OS
(Windows 2000)
Virtual Machine
Virtual Machine
Physical
Virtual Machine Manager
Host Operating System
System Hardware
Applications
Guest OS
(Windows 2003)
Virtual Machine
Major Players
• Microsoft Virtual Server 2005 R2,
Microsoft Virtual PC 2007
• Longhorn Server "Hypervisor"
• VMWare Workstation ($), VMWare Server,
VMWare Player, VMWare ESX ($)
• Xensource Xen
This Isn't New!
• Need in the early 80s for virtual machine
managers for PC-DOS/MS-DOS apps
• Very hard to do until 386 architecture
arrived
• The difference: a special "v86" mode
• Exploited by Windows 386, DesqView,
Windows 3, OS/2 2.x and even by
Windows NT
But It Stopped There…
• So the 386 was excellent at creating
bunches of imaginary 8086s
• But not at creating imaginary 386es!
• Rumors had it that a new chip, the 80486,
could virtualize itself
• But it never really happened; there wasn't
a Pentium-class chip that could fully
virtualize a Pentium-class chip
So How Does Virtual PC Do It?
• It should be impossible, then, to create
virtual machine managers
• But some smart folks figured it out
• The original tool that eventually became
Virtual PC actually emulated Pentiums on
a Mac
• Another group out of CMU figured another
way
But Virtual Machines are Limited…
• VMMs make Pentium-type systems simulate
more Pentiums
• But while they work by emulating hardware, they
do not emulate CPUs, as that would be far too
slow
• Thus, at some point the VMM has to hand
instructions ("opcodes") over to the actual
processor
• Much of the issue lies also in the four Intel
"rings" of privilege (3's the lowest, 0 most power)
Problem and Solution
• There are ten opcodes that can "get out of hand"
VMM wise
• Answer: new line of chips that include a new
"ring -1" privilege
• Intel: "Vanderpool" "VT" technology
• AMD: "Pacifica" or "V" technology
• AMD's implementation is a superset of Intel's
• Not compatible, so VMMs must recognize and
handle AMD and Intel changes, or just limit it self
to the common capabilities
More on V/VT
• Bottom line: we finally have Pentiums that
can fully virtualize Pentiums!
• Intel manages VM memory in software,
AMD does it in hardware
• Adding the 10 opcodes and "ring -1"
makes building VMWare, Virtual Server
and Xen much easier, and makes the
VMMs more reliable
Virtualization Overview
• Virtual Machine Guest Environment
Where VMs Live
• While not running, a VM is nothing more
than a set of files representing
– the hard disk(s) on a VM
– the contents of RAM when "snapshotted"
– configuration info
• Microsoft stores this in a file with the
extension ".vhd"
• VMWare uses ".vmdk"
VM Hard Disk Options
• Virtual Hard Disks
– Fixed
– Dynamic
• Virtual Hard Disk Features
– Snapshots
– Undo disks
– Differencing Disks/"Cloning" VMs
VM Networking Options
• Virtual
Networking
– None
– Internal
– External (Bridged)
– "Virtual subnets"
Virtual Machine Additions
• Installed after the guest OS
– Typically from installed IS image
– Improves VM performance
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•
•
•
•
•
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Enhanced SVGA video drivers
Improved mouse support
Drag-and-drop with the host
Time synchronization
MS name: "Virtual Machine Additions"
VMWare name: "VMWare Tools"
Can cause some real troubles when converting
MS<->VMWare, so remove them beforehand!
64-bit Support
• 64-bit host support
– Windows Server SE
and EE x64
• x64 eliminates
physical memory
restrictions
• 64-bit Virtual Machine
Manager
– Larger kernel address
space
64-Bit Benefit
• 64 bit OSes are quite useful, but…
• They present some compatibility issues
• For example, x64 Windows does not run
16 bit apps (and you'd be surprised how
many little apps are still 16 bit, including
installers!)
• Answer: create a VM with a 32-bit OS,
and you can run that 16-bit app
What About Licensing?
• Typically software vendors want you to buy a
license for every virtual machine or physical
machine you install the software on
• Microsoft offers preferential licensing options for
people using their OS software on their
virtualization platforms
• Confusingly, MS forbids creating VMs from
some of its OSes
• Check your licenses before implementing!
Virtual Server 2005 R2
• Features
– 64-bit host support
– Web-based management
– New support for Linux distributions
– Support for Microsoft clusters
• Limitations
– No 64-bit guest support
– No guest audio
– No guest USB
VS2005 R2 MSCS Host Support
• Support for Microsoft
Clustering Services
– Windows Server 2003
Enterprise Edition or
Datacenter Edition
• VS is MSCS clusteraware
– Eliminates single point
of failure
– Automatic VM startup
Virtual Server 2005 R2 SP1
• Intel-VT & AMD-V-Aware
– Better performance
– Better Linux interoperability
• VSS Support (backups while running)
• VHD Mounting on Host
• Improved Backup & DR
Windows Server 2003 R2
• Applies to any virtualization product running on
Windows Server 2003 R2
• VM licensing changes
– Windows Server 2003 Enterprise Edition R2
• Base OS
• Four additional VM OS
– Windows Server 2003 Datacenter Edition
• Unlimited VMs
– Even Vista Enterprise gets in the act!
• SQL Server (Enterprise) offers unlimited VMs as
well
Interop 1: P2V
• Take an existing physical server and make it run
as a virtual server
• Usually not very automatic, but it's possible and
getting better
– MS has a P2V wizard that works with Enterprise
Server 2003 R2
– VMWare has the "VMWare Converter" in free and forpay versions
• All P2V tools have improved immensely in the
past 18 months
• Good news coming soon in the MS world
Interop 2: MS/VMWare
• VMWare's free converter can change
vmdk files to and from vhd files
• In some cases Microsoft forbids this
license-wise, although of course there's no
physical barrier
• This will all probably settle out eventually
When Does Virtualization Make
Sense?
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Server consolidation
Lab and Deployment Testing
Training
Disaster Recovery
Server Sprawl
• New application = new (underutilized) server
Application
Application
File/Print
Application
File/Print
Database
Database
Application
Application
File/Print
Application
Application
Application
We can put multiple functions on a single box, but we tend not to
Server Consolidation
• Increase hardware
utilization
• Reduced costs
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–
–
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Fewer systems
Less power
Less cooling
Lower IT resources
• Reduced Infrastructure
– Fewer racks
– Fewer switches
Lab and Deployment Testing
• Build a test virtual network
infrastructure
• Duplicate physical model
– Same domain structure and
system names
– Virtual network clients
• Reduced physical system
requirements
– No need for 1-1 physical
systems
• Virtual networking
– Connects virtual systems
– Isolated from production
network
Training
• Present and reset training image
– Just reset the VM
– No need to reimage the systems
– Network isolation
Disaster Recovery
• Fewer servers to manage and recover/restore
– Reduces costs
• Server VMs are hardware independent
– Can be restored to other platforms
– No need to match primary site and secondary site
hardware
• VMs are encapsulated
– Faster
– Can be replicated between sites
– No need for bare-metal installs
Disaster Recovery
• Physical-to-VM recovery
– Restore physical backup to running VM
– Lower costs – no need for 1-to-1 physical
servers
• VM-to-VM recovery
– Protects against operating system/application
failure
– Recover failed VM on another server
Disaster Recovery
• How's it done?
• Remember, when inactive a VM is nothing
more than a folder full of files
• The only issue is how to get it backed up
• You can just take the server down for a bit,
but the better answer involves online
backup
• MS's answer (VS 2005 R2 SP1) is free,
VMWare's isn't
High Availability for Hosts
Primary Site
Recovery Site
Virtual Server Host Clustering
Primary Site
Recovery Site
Windows Server
Longhorn Virtualization
Windows Virtualization Platforms
VM 2
VM 3
VM 1
“Parent””
Virtualization
Platform and
Management
VM 2
“Child”
VM 2
“Child”
Virtual Server 2005 R2
Windows Server 2003
Hardware
Virtual
Hard Disks
(VHD))
Windows Hypervisor Benefits
• Better performance
– Small hypervisor
– Utilizes Processor virtualization
• Intel-VT and AMD-V, full opcode support
• Small host footprint
– Combine with Windows Server Core
– Headless Virtual Server Host
• Managed using RDP, WinRS or whatever
ESX Server vs. Windows Server
• Monolithic hypervisor
• Microkernel hypervisor
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–
–
–
– Simpler than a modern kernel
– Still complex
– larger hypervisor
– Contains its own drivers model
VM 1
(“Admin”)
VM 2
Simple partitioning functionality
Lightweight hypervisor
No third-party code
Drivers run within guests
VM 1
(“Parent”)
Virtualization
Stack
VM 3
Hypervisor
Drivers
Drivers
Drivers
Drivers
Drivers
Drivers
VM 2
(“Child”)
VM 3
(“Child”)
Drivers
Drivers
Drivers
Drivers
Drivers
Drivers
Hypervisor
Hardware
Hardware
Windows Server Virtualization
VMware ESX Virtualization
Windows Server & Xen-enabled Linux
Provided by:
OS
Applications
Applications
Applications
Windows
virtualization
MS/XenSource
Longhorn Server
Windows
Kernel
VSP
VMBus
Windows Server 2003,
“Longhorn””
Windows
Kernel
VSC
VMBus
Windows hypervisor
Server Hardware
Xen-enabled
Basic
Linux Kernel
Linux Kernel
VSC
Emulation
VMBus
ISV/IHV/OEM
Virtual Server vs WSL
Virtual Server 2005 R2
Windows Server Virtualization
32-bit VMs?
Yes
Yes
64-bit VMs?
No
Yes
Multi-processor VMs?
No
Up to 8 processor VMs
VM memory support?
3.6 GB per VM
Up to 32 GB per VM
No
Yes
Hot add memory/processors?
Hot add storage/networking?
No
Yes
Managed by System Center Virtual
Machine Manager?
Yes
Yes
Microsoft Cluster support?
Yes
Yes
Scriptable/Extensible?
Number of running VMs?
User interface
Yes, COM
Yes, WMI
64
Limited only by hardware
resources
Web Interface
MMC 3.0 Interface
System Center VM Manager
• Provides P2V
• Uses historical MOM info to identify the best
machines for P2Ving
• "Intelligent Placement" assists in identifying
which particular physical systems would best
host a given VM
• Optimizer helps you tune both a VM and its PM
to get the best throughput
• Maintains VHD repository
• Totally PowerShell-able!
Centralized Management for VS2005 & Windows Server
By Resource
Pool
By VM State
By Owner
By Creation
Date
By Operating
System
Intelligent Virtual Server Placement
Subset physical
hosts to
appropriate
resource pool(s)
Rank-ordered
recommendations of
physical hosts for
placement of virtual
machine.
End User Provisioning
Ability to control
owned virtual
machines
Thumbnails of
all owned virtual
machines
Virtualization FAQs
• Do I need to license Guest OSes?
– Guest OS must be licensed
– Clients need CALs
– The exception is Windows Server 2003 R2
Enterprise Edition, Datacenter Edition and
Vista Enterprise
• How does guest CPU licensing work?
– Virtual CPUs count toward CPU license
– Not physical host CPUs (!)
Virtualization FAQs
• Will host clustering be supported with the
Windows Server Hypervisor?
– Yes, WSL Hypervisor supports all of the
features in Virtual Server 2005 R2 +
• Is the Hypervisor included with Longhorn
Server?
– No. The Hypervisor is a separate download
that will be available within 180 days of the
windows Server Longhorn RTM
Virtualization FAQs
• Are Virtual Server VM images compatible
with the Windows Server Hypervisor?
– Yes. They use the same format, VHD
• Will the Windows Server Hypervisor
support 64-bit hosts and guests?
– Yes. Unlike VS2005 the hypervisor provides
x64 support for hosts and guest VMs.
Microsoft Virtualization
Infrastructure
Applications
Management
Interoperability
Licensing
Virtual server 2005 R2, Windows Server
Longhorn Hypervisor, Intel-VT & AMD-V
SoftGrid, Rapid no-touch deployment
System Center Virtual Machine Manager,
P2V, Intelligent resource utilization
Licensed .VHD format, XENSource
Windows Server 2003 R2 EE & DE,
Windows Vista
Thank You!
Mark Minasi
help@minasi.com
www.minasi.com
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