Disk drives are partitioned and labeled by the Solaris installation program as part of installing the Solaris release. You may need to use the format utility when:
Displaying slice information
Dividing a disk into slices
Adding a disk drive to an existing system
Formatting a disk drive
Repairing a disk drive
The main reason a system administrator uses the format utility is to divide a disk into disk slices. These steps are covered in Chapter 23, SPARC: Adding a Disk (Tasks) and Chapter 24, x86: Adding a Disk (Tasks).
See Table 21-6 for guidelines on using the format utility.