Chapter A. Glossary244 3ware Serial ATA RAID Controller User Guide• Carve size. The size over which a unit will be divided into volumes, ifauto-carving is enabled.• CLI. Command Line Interface. The 3ware CLI is a text program, ratherthan a GUI (graphical user interface), for Windows, Linux, and FreeBSD.It has the same functionality as 3DM, and can be used to view, maintain,and manage 3ware controllers, disks, and units.• Configuration. The RAID level set for a unit.• Controller ID number. The unique SCSI number in the Windowsenvironment, or the Channel number in the Linux environment, of aparticular controller. Typically assigned by the operating system.• Create an array. The process of selecting individual disk drives andselecting a RAID level. The array will appear to the operating system as asingle unit. Overwrites any existing unit configuration data on the drives.Note that in 3ware software tools, arrays are referred to as units.• DCB. Disk configuration block. This is 3ware proprietary RAID tableinformation that is written to disk drives that are in a RAID unit, singledisk, or spare. The DCB includes information on the unit type, unitmembers, RAID level, and other important RAID information.• Delete an array. Deleting an array (or unit) is the process of returning thedrives in a unit to individual drives. This erases the DCB informationfrom the drives and deletes any data that was on them. When a unit isdeleted from a controller, it is sometimes referred to as being “destroyed.”If you want to remove a unit without deleting the data on it, do not deleteit; instead use the Remove feature in 3DM, and then physically removethe drives.• Destroying. Same as deleting a unit.• Degraded unit. A redundant unit that contains a drive that has failed.• Disk roaming. When moving a unit from one controller to another, refersto putting disks back in a different order than they initially occupied,without harm to the data.• Distributed parity. Parity (error correction code) data is distributed acrossseveral drives in RAID 5 and RAID 50 configurations. Distributing paritydata across drives provides both protection of data and goodperformance.• Drive ID. A unique identifier for a specific drive in a system. Also called aport ID.• Drive Number. The SCSI number, or channel number, of a particulardrive.• ECC. Error correction code.
