Format a disk. 

• Any existing data is destroyed when you reformat a disk.

• The need for formatting a disk drive has decreased as more and more manufacturers ship their disk drives formatted and partitioned. You might not need to use the format utility when you add a disk drive to an existing system.

• If a disk has been relocated and is displaying many disk errors, you can attempt to reformat it. Reformatting automatically remaps any bad sectors.

How to Format a Disk

Replace a system disk. 

• Data from the damaged system disk must be restored from a backup medium. Otherwise, the system will have to be reinstalled by using the installation utility.

SPARC: How to Connect a System Disk and Boot, x86: How to Connect a System Disk, or, if the system must be reinstalled, Oracle Solaris 10 9/10 Installation Guide: Basic Installations

Divide a disk into slices. 

• Any existing data is destroyed when you repartition and relabel a disk with existing slices.

• Existing data must be copied to backup media before the disk is repartitioned and restored.

SPARC: How to Create Disk Slices and Label a Disk or x86: How to Create Disk Slices and Label a Disk

Add a secondary disk to an existing system. 

• Any existing data must be restored from backup media if the secondary disk is reformatted or repartitioned.

SPARC: How to Connect a Secondary Disk and Boot or x86: How to Connect a Secondary Disk and Boot

Repair a disk drive. 

• Some customer sites prefer to replace rather than repair defective drives. If your site has a repair contract with the disk drive manufacturer, you might not need to use the format utility to repair disk drives.

• The repair of a disk drive usually means that a bad sector is added to a defect list. New controllers remap bad sectors with no system interruption.

• If the system has an older controller, you might need to remap a bad sector and restore any lost data.

Repairing a Defective Sector