System Administration Guide: Devices and File Systems

SPARC: Adding a System Disk or a Secondary Disk

A system disk contains the root (/) or /usr file systems, or both. If the disk that contains either of these file systems becomes damaged, you have two ways to recover:

A secondary disk does not contain the root (/) and /usr file systems. A secondary disk usually contains space for user files. You can add a secondary disk to a system for more disk space, or you can replace a damaged secondary disk. If you replace a secondary disk on a system, you can restore the old disk's data on the new disk.