HP Surestore Disk Array FC60 HP SureStore E Disk Array 12H User's and Service - Page 265

Glossary I/O Operation Including A Disk JBOD Load Balancing L-DRV Logical Drive Logical Drive Number Loop Address LUN Glossary An Input/Output (I/O) Operation is an operation initiated by a host computer system during which data is either written to or read from a peripheral. The process of adding a Disk Module to the array configuration is called Including A Disk. The disk array cannot use a Disk Module until it has been included. Once included, the disk array begins using the Disk Module for data storage, even if you have not created a Logical Drive with the newly added disk capacity. As opposed to disk enclosures that offer Data Redundancy, an enclosure without a Disk Array Controller (or another type of RAID) is called Just a Bunch Of Disks, or JBOD. When a JBOD enclosure has a disk failure, data is lost. See Balancing. See Logical Drive. A Logical Drive is a portion of the array capacity that appears to the operating system as a physical disk. The entire array capacity can be divided into up to eight Logical Drives. Only capacity that has been assigned to a Logical Drive is available to the operating system. The data contained in each Logical Drive is spread across all disks in the array, so there is no direct correlation between a Logical Drive and any single physical disk in the array. A unique number (0-7) assigned to each Logical Drive on the disk array. This number is used by your operating system to identify each array Logical Drive. The unique ID of a node in Fibre Channel loop topology, sometimes referred to as a Loop ID. Also a status type in the FC Status Menu, showing the Loop Address of the FC-SCSI MUX. Logical Unit Number. For consistency with UNIX terminology, LUN is used interchangeably with Logical Drive. See Logical Drive. 265