Im also running a HP XW4600 system, now I needed todo this when I was running solaris on the host since it was not able to detect any hard drives. I have installed 111b on this system and prior versions have run, with the exception of a few builds due to iommu errors. But I know 111b runs on the xw4600. Look at the following fix in this post to fix the HD issue and I think you should be good to go:
http://www.sun.com/bigadmin/hcl/data/systems/details/3475.html 1: "Ryan Anderson" When using Solaris 10 x64 05/08, the SATA controller is not supported so you won't be able to see or install to its internal disk or see its DVD drive by default. However, all works well if you go into the BIOS under 'Storage Options' and change the disk mode to AHCI (recommended for better speed) or IDE mode. NOTE: AHCI mode support for DVD/CD devices was added to Solaris 10 05/08, so if you are using an older Solaris 10 x64 release, use IDE mode. -- This message posted from opensolaris.org
