Port on a Fibre Channel bridge device.

Nonvolatile memory-backing store is used to contrast with a cache; it is a volatile random access memory used to speed up I/O operations. Data held in a volatile cache must be replicated or saved to a nonvolatile backing store so that they can survive system crashes or power failures. Data collection stored on (usually removable) nonvolatile storage media for purposes of recovery in case the original copy of data is lost or becomes inaccessible. To be useful for recovery, a backup must be made by copying the source data image when it is in a consistent state.

Computer system containing online data to be backed up.

Data collection that constitutes a backup copy of a given set of online data.

An application program scheduling and managing backup operations.

Rules for how and when backup should be performed; backup policies specify information such as what files or directories are to be backed up, schedule of backups, devices and media that are eligible to receive backup, how many copies should be made, and action to be perform if backup doesn t succeed.

Time available for performing a backup; backup windows are typically defined by operational necessity. If data were to be used from 8 A.M. until midnight, then the window between midnight and 8 A.M. is available for making backup copies. In some cases a...