I was recently playing with what I thought was a relatively modern system: I was installing OpenSolaris 2008.05, using zfs root, onto a Sun Ultra 24, and using it as a Xen dom0 to host both OpenSolaris 2008.05 and Solaris guests.
None of these technologies is brand new, and I have pretty high confidence in each of them. So I was extremely frustrated when the system flaked out completely. It would become unresponsive (even to ping) while transferring large files (for example, an iso image to use for guest installation). It would reboot seemingly spontaneously, with no panic or stack trace.
Finally, Mark Johnson came to the rescue. The problem was that the Sun Ultra 24 comes with the BIOS set to present SATA disks as IDE. Which works OK. Until you boot the machine as a Xen dom0. And then everything goes south.
For the record, the BIOS setting to change is under the Integrated Devices (or maybe Integrated Peripherals?) menu on the Advanced tab, and the correct value is "AHCI."
And now I'm happy again.
