Hi All,

Windows Server 2008 Hyper-V, hypervisor-based server virtualization technology, allows you to make the best use of your server hardware investments by consolidating multiple server worklaods as separate virtual machines (VMs) running on a single physical machine. With Hyper-V, you can also efficiently run multiple different operating systems concurrently, on a single server, and fully leverage the power of x64 computing.

When you’re planning a virtualization infrastructure with Hyper-V, please be sure to stay within the supported limits below. In addition, the limits discussed in this document are highly dependent on the underlying hardware server configuration.

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Operating System Requirements

Windows Server 2008 includes Hyper-V as an available role. Hyper-V is included with:

· Windows Server 2008 Standard Edition (x64)

· Windows Server 2008 Enterprise Edition (x64)

· Windows Server 2008 Datacenter Edition (x64)

Note: That Hyper-V is an x64 Edition only technology and is not available for 32-bit (x86) or Itanium (IA64) editions.

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Hardware Requirements

· Hyper-V requires an x64 processor with Hardware-assisted virtualization. This is available in processors that include a virtualization option; specifically, Intel VT or AMD Virtualization.

· Hardware Data Execution Protection (DEP) is also required and must be enabled. Specifically, you must enable Intel XD bit (execute disable bit) or AMD NX bit (no execute bit).

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Virtual Machine Architecture Support

· Hyper-V offers support for:

o 32-bit (x86) operating systems

o 64-bit (x64) operating systems

Both 32-bit and 64-bit virtual machines can run concurrently.

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Memory:

· Windows Server 2008 Enterprise/Datacenter Editions

o System/Host Physical memory support: Up to 1 TB of physical memory

o Virtual Machine memory support: Up to 64 GB of memory per virtual machine

· Windows Server 2008 Standard Edition

o System/Host Physical memory: Up to 32 GB of physical memory

o Virtual machine memory support: Approximately ~31.5 GB total used for all running virtual machines

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Processors:

· Physical Processor support: Hyper-V is supported on systems with up to 16 logical processors; A logical processor can be a core or a hyper-thread. Examples include:

o Single processor/Dual core system = 2 logical processors

o Single processor/Quad core system = 4 logical processors

o Dual processor/Dual core system= 4 logical processors

o Dual processor/Quad core system=8 logical processors

o Quad processor/Dual core system= 8 logical processors

o Quad processor/Dual core, hyper-threaded systems=16 logical processors

o Quad processor/Quad core systems=16 logical processors

· Virtual Processor support: Up to 4 virtual processors per virtual machine

Note: Hyper-V may run on systems with greater than 16 logical processors; however these configurations are not supported.

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Networking:

· Up to 12 virtual network adapters per virtual machine

o 8 synthetic network adapters

o 4 emulated network adapters

· Each virtual network adapter can use either a static or dynamic MAC address

· Each virtual network adapter offers integrated VLAN support and can be assigned a unique VLAN channel

· Unlimited number of virtual switches with an unlimited number of virtual machines per switch

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Physical Storage:

· Hyper-V offers flexible storage support such as:

o Direct Attach Storage (DAS): SATA, eSATA, PATA, SAS, SCSI, USB, FIrewire

o Storage Area Networks (SANs): iSCSI, Fiber Channel, SAS

o Network Attached Storage (NAS)

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Virtual Hard Disks:

· Dynamically Expanding Virtual Hard Disks:

o Default type maximum size up to 2040 GB each

· Fixed Size Virtual Hard Disks:

o Maximum size up to 2040 GB each

· Pass-through disks

o No size limitation other than what is supported by the guest operating system

Virtual Storage Controllers:

· Virtual IDE

o Each virtual machine supports up to 4 IDE devices

o One IDE device must be a virtual disk (VHD or pass-through) for boot

· Virtual SCSI

o Each virtual machine supports up to 4 virtual SCSI controllers

o Each controller supports up to 64 disks for a total of 256 virtual SCSI disks PER virtual machine.

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Virtual Storage:

· Total storage per virtual machine:

o Using virtual hard disks, each virtual machine supports 512 TB of storage per vm

o Using pass-through disks, this number is even greater depending on what is supported by the guest operating system;

· Virtual Machine Snapshots:

o Hyper-V supports up to 50 snapshots per virtual machine

· Virtual Machine Boot

o Virtual machines must boot from a virtual IDE device; however, that device can be backed by a wide array of storage options including:

1. Direct Attach Storage (DAS): SATA, eSATA, PATA, SAS, SCSI, USB, FIrewire

2. Storage Area Networks (SANs): iSCSI, Fiber Channel, SAS

3. Network Attached Storage (NAS)

IMPORTANT: Although the I/O performance of physical SCSI and IDE can differ significantly, this is not true for the virtualized SCSI and IDE devices in Hyper-V. Hyper-V IDE and SCSI storage devices both offer equally fast high I/O performance when integration services are installed in the guest operating system.

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Virtual CD/DVD:

· Maximum number of virtual CD/DVDs: By default, each virtual machine is provided one virtual CD/DVD. However, each virtual machine can support up to 3 virtual DVD drives per virtual machine (on the virtual IDE bus only) as one IDE device must be used as a virtual boot device.

· Pass-through CD-DVD:

o For security purposes, only one virtual machine can access a physical CD/DVD at a time.

· Virtual CD/DVD:

o Hyper-V supports reading virtual CD/DVD .ISO files

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Virtual Serial (COM) Ports

· Each virtual machine supports up to 2 virtualized COM ports that can be used to communicate with a physical server (local or remote) via a serial named pipe.

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Virtual Floppy Drive

· Each virtual machine supports up to 1 virtual floppy drive

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Number of Virtual Machines:

· Supports up to 128 concurrent running virtual machines

· Supports up to 512 configured virtual machines

Nick.