As you may or may not know, I love clustering. I've been working with MSCS for a very long time, and I look at it as a way to make my daily life easier. An admin with a cluster can have downtime on hardware in the middle of the day, can do patches at any time knowing that if there's a problem, all you have to do is fail back to an unpatched node. That and it makes for some really cool toys.
Up to the present. I decided to check out MSCS (now known as failover clustering) on Windows Server 2008. I'm a big fan of building your own ISCSI devices, and I like Openfiler and FreeNAS. Both provide a large list of features, and the capability of Openfiler to run a two-node failover cluster of it's own (thus providing redundant storage for your cluster) to be a wonderful thing. So, you can imagine my dismay when I discovered that faliover clustering in Windows Server 2008 requires support for persistent reservations by your iSCSI target. Unfortunately, none of the free ISCSI target solutions support this yet. When they do, I'll be sure to update with more info.
Back to a blast from the past, clustering on windows server 2003. Here's another caveat for everyone out there: We'll often build our nodes with two disks in them and mirror those disks. Be careful about what method you use, some onboard RAID solutions will use BUS0 for their volumes. If this is the case with your RAID controller, switch to software mirroring. The reason is that the ISCSI initiator also latches on to BUS0, putting it on the same bus as your boot volume. This will cause cluster creation to pop up a warning about being unable to find a quorum device (BEWARE, no warning will pop up if you use the advanced creation option, you just won't be able to add any shared disks later).