At the risk of using a cost-analysis for a five-box hardware multi-boxer, you are probably better off just picking up some hard drives. Especially, if you wanted to try and do anything that might come close to falling under a "best practice" or "manufacturer supported/recommended" configuration. I'm also not sure what would be gained by running WoW off a NAS if the corresponding machines running WoW were not booted off that NAS as well. That is, diskless boot, no hard drives in any of the machines running WoW, which means we are now bluring the traditional line between NAS and SAN.

Unfortunately, diskless boot (also called Boot From SAN) isn't an easy or cheap thing to accomplish.

In the server world (read, datacenter) we could use a Fibre Channel Host Bus Adaptor that connects up to a rack full of hard drives and conveniently presents a disk to the computer that looks like a local disk. Most Fibre Channel HBA are more expensive then an entire computer that could run WoW. Not to mention the per port cost of a fibre channel drop. I think I could build a computer that would run a WoW slave cheaper then the fibre channel switch port without trying to hard.

On the cheaper side we have ISCSI Host Bus Adaptors (HBA) that would use a normal 1 gigabit ethernet switch port. Again, I think I could build a computer cheaper then most ISCSI HBAs, they aren't cheap.

Which means we would want to look for a software solution, which, fortunately, does exist. This software, usually downloaded to the computer using a PXE boot (or put on a USB key) will connect to an ISCSI Target (the NAS) and boot the computer. The cost of emBoot, now Doubletake, winBoot/i and cost of an Intel Server NIC that supports ISCSI booting would be, rounding down, about $100 per computer.

It is also worth mentioning that Intel and Broadcom have released server network adaptors that have this type of software in the network card. The Intel version is called ISCSI Remote boot, and the card will set you back about $100. For those still reading, go track down what a small hard drive cost.


With all that aside, I think there could be some interesting solutions thru the use of open source/free software. These solutions do require more time then other solutions, but if you were just going to use that time playing WoW you are probably ahead of the game to spend it here instead. I've looked at just this problem off and on over the past year and the pieces are starting to come together.


Call it a NAS, SAN, or File Server, if a dedicated computer were setup to provide for the hosting of disks to boot up computers, and store data files (the home file server), I think the cost could be worth it. Sun's OpenSolaris platform is seeming to fit this purpose very well. The appropriate technology buzzwords someone would want to look up are ZFS, L2ARC, COMSTAR (specifically, the iSCSI target, although the SAS target does look interesting). The cost of MLC based solid state disk are rapidly getting cheaper and lend themselves to an L2ARC. Someone setting this up would probably also want to look at using a single volume for the base operating system image and running the slaves off snapshots of that base volume.

The gPXE (http://www.etherboot.org) project has created an open source solution to boot strap a computer for an iSCSI boot and hand that information off to a supported operating system (Windows Vista, Windows 2008, WIndows 2003). For those experimenting with getting this running, install it and boot off a USB key first before trying to do PXE chain loading. The MSDN (Microsoft Developers Network) is your friend here, start experimenting with Windows 2008 as it supports installing directly to a ISCSI target. Using Vista you will have to install to a hard drive first, then image it up to your ISCSI server.

Also, don't install Vista with the SATA drives in AHCI mode if you are going to use it for an image. All attempts I've made just result in a blue screen when Vista loads up. Interestingly, this occurs exactly when the ahci driver is loading.

Make sure your network switch ports support 1 gigabit ethernet (no 100mbps ethernet for this experiment), and you might want to try and track down an old switch that support Link Aggregation Control Protocol (LACP) and have multiple 1Gb ethernet lines running to the NAS/SAN/file server. I'd start with two links, then move to three if necessary.


Without actually sitting down and running cost numbers, the boot from SAN and running WoW off a NAS/SAN concept probably makes more sense with more then five computers then it does with less then five computers. I don't really get the feeling it is worth it at five unless that SAN/NAS is used for several other purposes (boot up media centers, other computers in the house, serve as a general file server, etc).