AFAIK, there is no list. The only disk drives that are certain to work are the Apple Drive Module (ADM) disk drives. The official ADM disk bricks were 750 GB 7200-rpm SATA, 300 GB 15,000-rpm SAS, 80 GB 7200-rpm SATA, and 73 GB 15,000-rpm SAS. Beyond that, expect to need 3.0 Gbps SAS or SATA connections, and to either acquire disks from a vendor that'll test and support the disks, or expect to have to experiment with what you decide to get. As for what works, donno, try it. You'll find a few previous reports posted around the 'net, but different firmware revisions can mean even disks that supposedly do work might not. Or switch the approach here and install a Fibre Channel Storage Area Network (FC SAN) Host Bus Adapter (HBA), a fibre channel switch, and connect it all to a FC SAN storage controller, and connect your disks to the FC SAN storage controller — with that, you can likely still get disks compatible with the FC SAN controller, and might well be able to re-use that after you retire this Xserve.