Features of Windows Server Virtualization

Now that we understand something about how virtualization works (or will work) on Windows Server 2008, let’s look at what it can actually do. Here’s a quick summary:

• Creates and manage child partitions for both 32-bit (x86) and 64-bit (x64) operating systems.

• Creates VMs that can use SMP to access 2, 4, or even 8 cores.

• Creates VMs that use up to 1 TB of physical memory. Windows Server virtualization can do this because it’s built on 64-bit from the ground up. That means 64-bit HV, 64-bit virtualization stack, and so on.

• Supports direct pass-through disk access for VMs to provide enhanced read/write performance. Storage is often a bottleneck for physical machines, and with virtual disks it can be even more of a bottleneck. Windows Server virtualization overcomes this issue.

• Supports hot-add access to any form of storage. This means you can create virtual storage workloads and manage them dynamically.

• Supports dynamic addition of virtual NICs and can take advantage of underlying virtual LAN (VLAN) security.

• Includes tools for migrating Virtual Server workloads to Windows Server virtualization. This means your current investment in Virtual Server won’t go down the drain.

• Supports Windows Server 2008 Core as the parent OS for increased security. I said this earlier, but it bears repeating here because it’s important.

• Supports NAT and network quarantine for VMs, role-based security, Group Policy, utilization counters, non-Microsoft guests, virtual machine snapshots using Volume Shadow Copy Service (VSS), resource control using Windows System Resource Manager (WSRM), clustering, and a whole bunch of other things.

To put this all in perspective, take a look at Table 3-1, which provides a comparison between Virtual Server 2005 R2 and Windows Server virtualization.

Table 3-1: Comparison of Virtual Server 2005 R2 and Windows Server Virtualization Features
Open table as spreadsheet

Feature	Virtual Server 2005 R2	Windows Server Virtualization
32-bit VMs	Yes	Yes
64-bit VMs	No	Yes
SMP VMs	No	Up to 8 core virtual machines
Hot-add memory	No	Yes
Hot-add processors	No	Yes
Hot-add storage	No	Yes
Hot-add networking	No	Yes
Max memory per VM	3.6 GM	> 32 GB
Cluster support	Yes	Yes
Scripting support	Using COM	Using WMI
Max number of VMs	64	No limit-depends only on hardware
Management tool	Web UI	MMC snap-in
Live migration support	No	Yes
Works with System Center Virtual Machine Manager	Yes	Yes

Note 

Virtual Server 2005 R2 Service Pack 1 will support Intel VT and AMD-V technologies, as well as VSS.