directory junction

(Windows specific term) Directory junctions use the reparse

 

point concept of Windows. An NTFS 5 directory junction allows

 

you to redirect a directory/file request to another location.

disaster recovery

A process to restore a client’s main system disk to a state close

 

to the time when a (full) backup was performed.

Disk Agent

A component needed on a client to back it up and restore it.

 

The Disk Agent controls reading from and writing to a disk.

 

During a backup session, the Disk Agent reads data from a disk

 

and sends it to the Media Agent, which then moves it to the

 

device. During a restore session the Disk Agent receives data

 

from the Media Agent and writes it to the disk.

Disk Agent

The number of Disk Agents that are allowed to send data to one

concurrency

Media Agent concurrently.

disk discovery

The detection of disks during client backup with disk discovery.

 

During this backup, Data Protector discovers (detects) the disks

 

that are present on the client — even though they might not have

 

been present on the system when the backup was configured

 

— and backs them up. This is particularly useful in dynamic

 

environments, where configurations change rapidly. After the

 

disks are expanded, each inherits all options from its master

 

client object. Even if pre- and post-exec commands are specified

 

once, they are started many times, once per each object.

disk group

(Veritas Volume Manager specific term) The basic unit of data

 

storage in VxVM system. A disk group can consist of one or

 

more physical volumes. There can be more than one disk group

 

on the system.

disk image

A high-speed backup where Data Protector backs up files as

(rawdisk) backup

bitmap images. A disk image (rawdisk) backup does not track

 

the files and directory structure stored on the disk, but stores a

 

disk image structure on byte level. You can perform a disk image

 

backup of either specific disk sections or a complete disk.

disk quota

A concept to manage disk space consumption for all or a subset

 

of users on a computer system. This concept is used by several

 

operating system platforms.

disk staging

The process of backing up data in several phases to improve

 

the performance of backups and restores, reduce costs of storing

Concepts guide

359