HP StorageWorks 12000 User Manual page 250

disk array Two or more hard drives combined as a single logical unit for increased capacity,
speed, and fault-tolerant operation. Disk arrays are logically grouped into a
storage pool.
disk mirroring Also known as data mirroring.
disk striping The process of dividing a body of data into blocks and spreading the data blocks
across several partitions on several disks.
disk-to-disk The backing up data on disks rather than on tape. Disk-to-disk backup systems
backup provide a very fast single file restore capability compared with disk-to-tape
backup.
disk-to-disk-to-tape The process of archiving in which data is initially copied to backup storage on
backup a disk-based storage system, such as a VLS, and then periodically copied again
to a tape storage system.
dynamic disk A finely-tuned filesystem developed to handle large block I/O typical of a
filesystem streaming backup and restore environment. This filesystem is optimized for
sequential access and very large file sizes.
data migration The process of moving data from one storage device to another, such as migrating
data from virtual media to physical media.
deduplication The process of eliminating duplicate data from the backups on a virtual cartridge
to reduce the amount of disk space required.
dual port virtual Virtual devices (for example, the two host or device ports on each FC card in
devices the node) with connectivity to two ports so that the device can be connected to
more than one input or output.
echo copy A software feature within automigration that automatically synchronizes the
physical cartridges to matching virtual cartridges (with the same barcodes) based
on user-defined policies, and is totally transparent to the backup application.
(Echo copy is similar to mirror copy.)
extent The minimum amount of disk space allocated for writing by the VLS dynamic
disk filesystem. A smaller extent reduces wasted disk space, but decreases restore
performance. The VLS extent size is 32MB.
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.
Fibre Channel A serial data transport infrastructure and protocol used to implement storage
area networks (SANs).
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.
250 Glossary