Data Protector Express User's Guide (TC330-96002, October 2010)

a textual description of its current setting. To customize the settings for an interval , click on one of the
interval buttons. Most schedules are defined in terms of the following intervals:
Daily — run on sequential weekdays.
Weekly — run once per week on the day specified by the user, for example, Friday.
Monthly — run once per month on a day specified by the user such as the first day, the last day, the first
Monday, and others. You can also specify how many months s hould elapse between monthlies. Setting
the monthly interval to every 3 months will create a backup ever y quarter.
Yearly —runonceperyearonaspecified day of the year. By increasing the interval you c an also
schedule a job to run once every so many years.
NOTE:
There are also Hourly and Minutely intervals that are less commonly used. The concepts behind using
them are similar to those of the intervals discussed above.
For all intervals there is a setting that controls the number of sets. This settings determines how many sets of
that backup interval will be created before Data Protector Express goes back and overwrites the first. For
example, if your schedule starts in January and calls for three monthly sets, you will have a set for January,
a set for February, and a set for March. In April, the job will overwrite the set from January.
When configuring a rotation the Calendar view displays the schedule graphically. The interval type for
each day is displayed in the calendar. Clicking on a day in the calendar will display the type of backup,
thewritemode,andthenameofthemediathatwillbeusedonthatday.
TIP:
You ca n change the interval for a given day of a schedule by right-clicking on the day in the calendar
and selecting the desir ed type.
You can prevent the job from running on a given day. This is helpful for times when you know the job won’t
completebecauseyouwon’tbeabletosupplytherightmediaforthejob—asinthecaseofholidays.
You can enable or disable jobs from running on specified days of the week by clicking the name of the day
in the heading of the c alendar view. For example, if you want daily backups on Saturdays.
Implications for Restoring Data
Intervals also define the g ranularity of the data you can restore. Rotations are set up to capture m ore
granularity in the recent past and less granularity as data gets older. Larger intervals, like Yearly and
Monthly, produce lower granularity data history. Smaller intervals, like Daily, produce higher granularity
history. Take, for example, a rota tion with three full monthly backup sets on the last day of each m onth,
four full weekly backup sets created on each Friday, and four incremental daily backup sets created
Monday through Thursday. Now suppose you have a critical file that changes daily. On Wednesday,
you are asked to retrieve the file as of a specific date. With this rotation you can roll back to the Monday
and Tuesday versions of the file in the current week and the Wednesday, Thursday, and Friday versions of
the file in the previous week. Beyond that, you will only have the versions of the file as they existed on
Friday for the previous four weeks previous to the current week. And b eyond that you will only have the
versions of the file that existed on the last day of the month for the previous three months.
The catalog keeps track of the files and versions that have been backed up so you don’t have to
rememb er what me dia they are on. This knowledge makes the restoration process very simp le. You only
need to specif y the files you want restored and Data Protector Express will prompt you for the m edia
it needs restore the files. Full reconstruction of data may require multiple m edia sets. For example, to
reconstruct the data for a Wednesday from a GFS 20 set rotation type, you will require the full backup
media set from the previous end of week and all of the incremental media sets from that week (that is,
Mondays, Tuesdays and Wednesdays). In some circumstances, the preceding full backup media set
User’s Guide
51