SCSI-2 drives do not require a format.dat entry. Starting with the Solaris 2.3 release, the format utility automatically configures the SCSI-2 drivers if the drives are powered on during a reconfiguration boot. See "How to Automatically Configure a SCSI Drive" for step-by-step instructions on configuring a SCSI disk drive automatically.
If your disk was not recognized, use a text editor to create an entry in format.dat for the disk. You'll need to gather all the pertinent technical specifications about the disk and its controller before you start. This information should have been provided with the disk. If not, contact the disk manufacturer or your supplier. See Chapter 32, The format Utility (Reference) for more information on adding an entry to the /etc/format.dat file.