HP Data Protector Express Basic-Software - Manual (Page 27)

Rotation type and Sets
This setting is only available when the job is scheduled to run repeatedly. The Rotation type and Sets
controls allow you to specify a set of preconfigured rotations. The Custom Rotation type is a special
case. It unlocks the user interface to allow the user to configure his own rotation. For more information
about setting up rotations, see Chapter 7 .
Type of fixed rotation
This setting is only available when creating a custom rotation. For more information about setting up
rotations, see Chapter 7 .
Mode Settings
The Mode box contains several settings the control the type of backup and automatic verify that will be
performed, how used media will be treated, and what to do when a file won’t fit on the current media.
Man of these settings are set automatically when a schedule rotation is in effect. When a rotation controls
theses settings they become disabled in the Administrator.
Backup mode
Data Protector Express supports the back modes listed below. For scheduled automatic rotation jobs,
Data Protector Express uses the backup mode for each backup set as indicated on the Schedule page; for
unscheduled or manual jobs, Data Protector Express uses the settings set by the user.
Full This setting instructs Data Protector Express to back up all selected files.
Differential This setting instructs Data Protector Express to back up all selected files that have changed
since the last full backup.
Incremental This setting instructs Data Protector Express to back up all selected files that have changed
since the last full, differential, or incremental backup.
Copy This setting instructs Data Protector Express to back up all selected files, but it has no effect on any
future scheduled job. Use this option when you wish to make a record of files or systems at a particular
time, but do not wish to disrupt the normal backup schedule.
CAUTION:
Incremental jobs are the shortest and smallest jobs to run, but they present some issues related to full data
recovery. The difference between an incremental and a differential backup is important -- incremental
backup jobs back up only files that have changed since the last full, differential or incremental backup,
while differential backup jobs back up all files changed since the last full backup. If incremental backup
media sets are overwritten or recycled before another full backup is performed, this can create a gap in
available data if you need to recover files from the overwritten media.
Exclusive use of incremental backup jobs to ensure full data recovery after a disaster is not recommended,
unless you are using a schedule that retains one full backup and all subsequent incremental backups
before overwriting any media. However, to ensure successful data recovery with incremental jobs, follow
these guidelines:
Have at least as many incremental media as there are days between full or differential backup jobs. For
example, if you run full backup jobs every five days, have at least four incremental media; if you run full
backup jobs every seven days, have at least six incremental media.
Never recycle incremental media between differential or full backup jobs. If you run more than one
incremental job in a row, be certain to not recycle any of the media used during this string of incremental
jobs.
User’s Guide 27