The Xserve G5 has a remote diagnostics tool that runs in Open Firmware, similar to the Apple Hardware Test (AHT) found on most OS X installation disks that ship with Macs, or now baked into the EFI on most new Intel based Macs. The depths of testing and detailed results of the Xserve Remote Diagnostics far exceed AHT, but so does the complexity of setting it up.

Normally, this very comprehensive testing suite can require up to 2 additional machines; the first machine to administer the test and the second OS X Server running Netboot. Both administration and Netboot serving can be performed from the same Mac. The fact that I can’t run these tests without additional machines bothers me, but setting up another server just for Netboot is wholly impractical.

Thankfully a set of instructions showing how to create a bootable CD in lieu of Netbooting are available. The process involves creating a disk image from parts of the Xserve Remote Diagnostics software. The resulting image is small and generic to any Xserve G5, so much so that I couldn’t figure out what the point was of telling people how to do it instead of just letting them download the completed image.

To that effect I’ve compiled all the necessary parts here, including the bootable disk, so that it?s easier to perform these tests:

– Apple Supplied Documentation (alt)
– Xserve Remote Diagnostics 1.0.4 (alt)
– Xserve Remote Diagnostics 1.0.4 Boot Disk

The following basic steps should help:

1. Download and read the Apple documentation.
2. Download and install the diagnostics software on a Mac that is within the same subnet as the Xserve to be tested.
3. Download and burn the boot disk image to CD.
4. Put the burned CD into the Xserve and restart it while holding down the C key. The CD will not appear in the list of bootable devices while holding down the option key, or as an option in Startup Disk. Once booted from the disk you’ll see a gray screen with some text at the top.
5. Make sure the administrative computer with xrdiags is on the same subnet as the Xserve, you might have to directly connect to its first (lower) Ethernet port and set your subnet to 0.0.0.0 if the Xserve is not detected when running xrdiags -d.
6. Once the tests are running prepare for a long wait. The documentation says 5 minutes for the Quick test and 15-20 for an Extended one. A Quick test on an Xserve G5 with 8 GB of RAM took 45 minutes; an Extended test took over 3 hours. This was a terrible discovery late at night.

Hopefully this will help someone