Unrecognized disks cannot be formatted without precise information about the disk's geometry and operating parameters. This information is supplied in the /etc/format.dat file.
SCSI-2 drives do not require a format.dat entry. Starting with 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 25, The format Utility (Reference) for more information on adding an entry to the /etc/format.dat file.