An Apple support note says that its Xserve Diagnostics Mac OS X Tools Version 3X104 are not supported with Snow Leopard Server.
If you have upgraded your Xserve to Mac OS X v10.6 Snow Leopard Server, you should not use Apple Xserve Diagnostics Mac OS X Tools version 3X104. You should use Apple Xserve Diagnostics EFI Tools version 3X104 instead.
Xserve Diagnostics Mac OS X Tools let managers run down issues in the Boot ROM, Ethernet controller, fans, hard drives, power supply, processor, RAM, sensors, USB ports and video controller board. But where is the EFI Tools?
There's no need for confusion here. Remember back on Xserve Apple Xserve Diagnostics User Guide for Version 3X104 Chapter 1, Page 5.
You can run AXD in Extensible Firmware Interface (EFI), which is referred to as AXD EFI tools, or in Mac OS X or Mac OS X Server, which is referred to as AXD Mac OS X tools.
By running AXD EFI tools, you can diagnose hardware issues that prevent Mac OS X Server from successfully starting up. You can also run tests without interference from Mac OS X Server and test more than 2.5 gigabytes (GB) of memory. However, AXD Mac OS X tools provides an enhanced interface and has more extensive sensor, hard drive, and video controller tests. For a detailed comparison and description of all available tests, see “AXD Tools Test Reference” on page 35.
So it's the same tests but a different interface. And the support note put caps on the Tools.