The iSCSI Initiator that we use for connecting Windows to iSCSI targets has a friend. It’s called Microsoft Windows Storage Server, which you can use to turn a DAS RAID in a Windows box into a LUN for iSCSI. Good stuff. Check out the data sheet here:
download.microsoft.com/download/d/8/4/ d84b1c50-e0bb-45ba-b2f4-356f4f456a88/WUDSS%20Datasheet_Final.doc
Now that’s not to say they’re the only game in town. iSCSI Target is also a feature of OpenSolaris:
http://opensolaris.org/os/project/iscsitgt/
And there’s a nifty little Open Source Project called iSCSI Enterprise Target:
http://sourceforge.net/projects/iscsitarget/?abmode=1