HP StorageWorks 1000i Virtual Library System - Manual (Page 118)

disk array Two or more hard drives combined as a single logical unit for increased
capacity, speed, and/or fault-tolerant operation. Disk arrays are logically
grouped into a storage pool. See also storage pool.
disk mirroring A technique in which data is written to two duplicate disks simultaneously.
Mirroring provides data protection in the case of disk failure, because data is
constantly updated to both disks. This way if one of the hard drives fails, the
system can instantly switch to the other disk without any loss of data or service.
See also RAID 1-level data storage and failover protection.
disk striping The process of dividing a body of data into blocks and spreading the data
blocks across several partitions on several disks. See also RAID.
disk-to-disk
backup
Typically refers to backing up data on disks rather than on tape. Disk-to-disk
backup systems provide a very fast single file restore capability compared with
disk-to-tape backup. See also data restore and virtual tape.
disk-to-disk-to­
tape backup
Archiving in which data is initially copied to backup storage on a disk-based
storage system, such as a VLS, and then periodically copied again to a tape
storage system. See also data migration.
DVD drive
E-mail Short for electronic mail, the transmission of messages over communications
networks.
emulation Refers to the ability of a program or device to imitate another program or device.
Ethernet A widely implemented local area network (LAN) protocol that uses a bus or star
topology and serves as the basis for the IEEE 802.3 standard, which specifies
the physical and software layers. Baseband LAN allows multiple station access
to the transmission medium at will without prior coordination and which avoids
or resolves contention.
extent The minimum amount of disk space allocated for writing by the VLS dynamic
disk files system. A smaller extent reduces wasted disk space, but decreases
restore performance. The VLS extent size is 32 MB. See also data restore.
failover protection A backup operational mode in which the functions of a system component (such
as a hard drive or power supply) are assumed by secondary system components
when the primary component becomes unavailable through either failure or
scheduled down time.
file A VLS file is a virtual cartridge.
Firesafe The holding area for virtual media that is not assigned to a virtual library. Data
cannot be restored from virtual media located in the Firesafe until the media is
moved into a library.
hot plug The ability to add and remove devices to an appliance while the appliance is
running and have the operating system automatically recognize the change.
infrastructure The physical hardware used to interconnect computers. Infrastructure also
includes the software used to send, receive, and manage the signals that are
transmitted.
initiator Media (host) server that runs the backup/restore application that passes
commands and data between the network and the VLS.
inputs/outputs per
second
A measure of performance for a host-attached storage device or RAID controller.
IP address Internet Protocol Address. Unique string of numbers (in the format
xxx.xxx.xxx.xxx) that identifies a device on a network.
118 Glossary