Appendix A. Glossary232 3ware 9550SX Serial ATA RAID Controller User Guide 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. 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. ECC Error policy. Determines whether an error detected during a rebuildstops the rebuild or whether the rebuild can continue in spite of the error. EMS (Enclosure Management Services). Chassis-monitoring functionsfor environmental, power, mechanical monitoring, and control using theI²C bus port. Export a unit. To remove the association of a unit with a controller. Doesnot affect the data on the drives. Used for array roaming, when you wantto swap out a unit without powering down the system, and move the unit
