StarWind Free is an iSCSI Target that converts any Windows server into a SAN in less than 10 minutes. This is a fully functional product at no cost.
• Large 2 TB storage capacity
• Unlimited number of connections
• Virtualization environment support for VMware, Hyper-V, XenServer, Virtual Iron
• Enhances VMware environments by enabling VMotion, VMware HA, DRS and VCB
• Supports Windows server clustering for any application including SQL Server, Exchange, SharePoint
Get it here: Convert Windows Servers into Shared Storage