HP 12000 User Manual page 195

deduplication The process of eliminating duplicate data from the backups on a virtual cartridge to reduce the
amount of disk space required.
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 provide a very
backup fast single file restore capability compared with disk-to-tape backup.
disk-to-disk-to-tape backup
The process of 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.
dual port virtual Virtual devices (for example, the two host or device ports on each FC card in the node) with
devices connectivity to two ports so that the device can be connected to more than one input or output.
dynamic disk A finely-tuned filesystem developed to handle large block I/O typical of a streaming backup and
filesystem restore environment. This filesystem is optimized for sequential access and very large file sizes.
E
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.
See also data restore..
F
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.
fault tolerance The capacity to cope with internal hardware problems without interrupting the system's data
availability, often by using backup systems brought online when a failure is detected. Many
systems provide fault tolerance by using RAID architecture to give protection against loss of data
when a single disk drive fails. Using RAID 1, 3, 5, 6, 10, or 50 techniques, the RAID controller
can reconstruct data from a failed disk drive and write it to a spare or replacement disk drive.
Fibre Channel A data transfer architecture designed for mass storage devices and other peripheral devices that
require high bandwidth.
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.
H
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.
I
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 A media (host) server that runs the backup/restore application that passes commands and data
between the network and the VLS.
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