Windows Server blog by Kurt Roggen [BE]

Q: What is the option “Enable spoofing of MAC addresses” on a virtual network adapter?
A: A virtual network adapter can send/receive packets containing any MAC address.  Equivalent of putting adapter in promiscuous mode.
More information: http://blogs.technet.com/jhoward/archive/2009/05/21/new-in-hyper-v-windows-server-2008-r2-part-2-mac-spoofing.aspx

Q: What is the “Processor Compatibility” feature?
A: Allows more hardware flexibility/mobility between Hyper-V hosts when moving VMs by reducing the CPU instruction set to a common level set. Works only within same CPU family (Intel-to-Intel, AMD-to-AMD). Is a key feature for flexible Live Migration.
More information: http://blogs.msdn.com/b/virtual_pc_guy/archive/2009/06/09/processor-compatibility-in-hyper-v-r2.aspx

Q: What is the “Network Optimizations” feature?
A: With VMM 2008 R2, you can take advantage of network optimization capabilities that are available on hosts that are running Windows Server 2008 R2 Hyper-V. VMM 2008 R2 supports both the Virtual Machine Queue (VMQ) and TCP Chimney features, which improve network performance for virtual machines. Network Optimizations is configurable at the VM level and is visible for capable virtualisation hosts during the virtual machine Intelligent Placement wizard.
More information: http://technet.microsoft.com/en-us/library/ee236499.aspx

Q: What is VMQ (Virtual Machine Queue)?
A: Network adapters that support the VMQ (Virtual Machine Queue) feature can create a unique network queue for each virtual network adapter and then connect that queue directly to the virtual machine’s memory. This connection routes packets directly from the hypervisor to the virtual machine, bypassing much of the processing in the virtualization stack.

Q: Can I use SCVMM to insert my Hyper-V host into a the Hyper-V cluster?
A: No, you still need to complete most cluster related tasks using the Failover Cluster Manager console.

Q: What is Storage Quick Migration (SQM)?
A: Allows the migration of the storage of VM from one location to another with under 1 minute downtime in most cases. The virtual machine can remain running for the almost the entire duration of the transfer of its (read-only) virtual disks from once storage location to another.  The virtual machine is put into saved-state for a short period to migrate its memory state and associated differencing disks.
More information: http://blogs.technet.com/b/virtualization/archive/2009/06/25/system-center-virtual-machine-manager-2008-r2-quick-storage-migration.aspx

Q: What are CSV (Clustered Shared Volumes)?
A: Allows for storing multiple Hyper-V VMs, their configuration, snapshots, etc… per LUN by providing coordinated distributed access to a cluster shared volume through a single consistent namespace (C:\ClusterStorage) which is shared among all nodes in the cluster. CSV avoids the “LUN management nightmare”.
More information: http://blogs.msdn.com/b/clustering/archive/2009/03/02/9453288.aspx

Q: Does SCVMM 2008 R2 support CSV?
A: Yes, SCVMM even recognizes the difference between an owner (coordinator) node and non-owner node when deploying VMs to the Hyper-V cluster nodes. When deploying a VM, the VHD is deployed to the Hyper-V CSV owner (coordinator) node first, while the VM is created on the host selected during the VM creation wizard (Intelligent Placement) within SCVMM.

Q: I’m using diskshadow.exe to backup my virtual machines using the Hyper-V VSS Writer.  Can I also use it with CSV disks?
A: No, unfortunately DiskShadow is not compatible with CSV in Win2008 R2. You can only do CSV backups from coordinator node safely which is the only node that has access to the (Hyper-V) VSS writer. Windows Server Backup does also not support backing up virtual machines on Cluster Shared Volumes (CSV volumes).

Related reading:

• System Center Virtual Machine Manager (VMM) Q&A – Part 1