Hardware and Software Requirements for Clustering

All vSphere MSCS configurations require certain hardware and software components.

The following table lists hardware and software requirements that apply to all vSphere MSCS configurations.

Table 1. Clustering Requirements

Component	Requirement
Virtual SCSI adapter	LSI Logic Parallel for Windows Server 2003. LSI Logic SAS for Windows Server 2008 SP2 and above. VMware Paravirtual for Windows Server 2008 SP2 and above.
Operating system	Windows Server 2003 SP1 and SP2, Windows Server 2008 SP2 above releases. For supported guest operating systems see Other Clustering Requirements and Recommendations.
Virtual NIC	VMXNET3 is required. You must activate in-guest Windows Receive Side Scaling (RSS) on the virtual NIC. Note: Drivers, improvements and updates to the VMXNET3 virtual NIC are delivered through VMware Tools. Upgrade to the latest version of VMware Tools on any VM using the VMXNET3 virtual NIC.
I/O timeout	Set to 60 seconds or more. Modify HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Disk\TimeOutValue. The system might reset this I/O timeout value if you re-create a cluster. You must reset the value in that case.
Disk format	Select Thick Provision to create disks in eagerzeroedthick format.
Disk and networking setup	Add networking before disks.
Number of nodes	Windows Server 2003 SP1 and SP2 : two-node clustering Windows Server 2008 SP2 and above: up to five-node clustering For supported guest operating systems see Other Clustering Requirements and Recommendations.
NTP server	Synchronize domain controllers and cluster nodes with a common NTP server, and deactivate host-based time synchronization when using clustering in the guest.