Dario IT Solutions Blog

After a couple of complex deployments, I would like to share some of our findings and recommendations.

Quick Migrations & Clustering:

1. Make sure you install this hotfix if you plan on using Failover Clusters.
2. SCVMM does not support managing virtual machines if there is more than one virtual machine in a cluster group.
3. Physical disk resource for the pass-through disk should be moved to the failover cluster node that hosts the virtual machine before it is added to the configuration of that virtual machine.
4. Parent and child VHDs must be on disks that are in the same Services or Applications group as the virtual machine resource.
5. To enable independent migration and failover of virtual machines with Microsoft Hyper-V, one storage LUN must be dedicated to each virtual machine.

Storage:

1. If you need to expose the LUNs directly to a VM, your shared storage must be an iSCSI SAN (no Virtual HBA is supported in Hyper-V)
2. Disk GUIDs can overcome the drive letter shortage but are terrible to use.
3. 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.
4. Virtual machine must use a virtual IDE device as the startup disk to start the guest operating system but you have many options to choose from when selecting the physical device that will provide the storage for the virtual IDE device.
5. To use the native disk support included in Failover Clustering, use basic disks, not dynamic disks.

Network:

1. Vendor NIC Teaming like the HP Network Configuration Utility is currently not working correctly with Hyper-V as a result of the different way the Hyper-V management partition communicates with the network drivers. I was told that Microsoft is well aware of this and is looking into it. It takes two to tango in this case which might complicate things working towards a quick fix.
2. Legacy network adapter is required if a virtual machine needs to boot from a network.
3. Hyper-V does not support wireless networks.
4. Network adapters must be dedicated to either network communication or iSCSI, not both. Moreover, You cannot use teamed network adapters, because they are not supported with iSCSI.

Some notes for more complex scenarios:

1. Check out Sanbolic Kayo FS. It can be used to enable shared access to a SAN volume from multiple physical host servers (or in other words – VMFS-like functionality for Microsoft Hyper-V)
2. For GeoClustering, check out Double-Take and their new offerings for Hyper-V.

Related posts:

1. Windows Server 2008 Hyper-V Storage
2. Hyper-V : Notes and Guidelines from the field
3. Booting an Hyper-V guest from an iSCSI LUN
4. Hyper-V Failover Clustering Using Normal Shares
5. Support Policies and Recommendations for Exchange Servers in Hardware Virtualization Environments