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CHAPTER 3
Managing Disk Volumes
This chapter describes redundant array of independent disks (RAID) concepts, how
to manage disk volumes, and how to configure hardware mirroring using the
on-board Ultra-4 SCSI controller.
This chapter contains the following sections:
■“Disk Volumes” on page 51
■“Volume Management Software” on page 52
■“RAID Technology” on page 54
■“Hardware Disk Mirroring” on page 56
■“Physical Disk Slot Numbers, Physical Device Names, and Logical Device
Names” on page 57
■“To Create a Hardware Disk Mirror” on page 57
■“To Delete a Hardware Disk Mirror” on page 59
■“To Perform a Mirrored Disk Hot-Plug Operation” on page 61
■“To Perform a Non-Mirrored Disk Hot-Swap Operation” on page 62

Disk Volumes

Disk volumes are logical disk devices comprising one or more physical disks or
partitions from several different disks.
Once you create a volume, the operating system uses and maintains the volume as if
it were a single disk. By providing this logical volume management layer, the
software overcomes the restrictions imposed by physical disk devices.
Sun’s volume management products also provide RAID data redundancy and
performance features. RAID is a technology that helps protect against disk and
hardware failures. Through RAID technology, volume management software is able
to provide high data availability, excellent I/O performance, and simplified
administration.