Selecting A Rotation Type - HP BB118BV - StorageWorks Data Protector Express Package User's Manual & Technical Reference

Fixed Rotation Types
Not fixed Media sets are named for the interval that has been run. They follow the form [Interval ]
Set [ number ].
For example, the first time an hourly backup job runs, the name of the media set will be "Hourly Set 1." Other
examples are "Daily Set 1," "Weekly Set 1," "Monthly Set 1," and "Yearly Set 1."
Fixed by day of week
media set is "1st Monday." An example of a weekly media set is "1 st Week of the Month." An example
of a monthly media set is "1st Month." An example of a yearly media set is "Yearly 1."
Fixed by week of month
Hour." An example of a daily media set is "Monday 1st Week." An example of a weekly media set
is "1 st Week of the Month." An example of a monthly media set is "1st Month." An example of a
yearly media set is "Yearly 1."
Fixed by day of month
media set is "1 st Day of the Month." An example of a weekly media set is "1 st Week of the Month." An
example of a monthly media set is "1st Month." An example of a yearly media set is "Yearly 1."
Fixed by day of year
media set is "Day 1 of the Year." An example of a weekly media set is "1 st Week of the Month." An
example of a monthly media set is "1st Month." An example of a yearly media set is "Yearly 1."
Each of these media rotations either relies on a predefined set count as described or makes use of the set
count in the interval. To change the interval's set count select the interval and enter the number of sets
you want to keep in the Number of rotation sets field. When a rotation runs out of sets it starts again
at set one and overwrites the media for set one.
Since a set may span multiple media you should not assume that a set is equal to a single piece of
media. Generally you should multiply the number of media sets by the number of pieces of media that a
single backup job uses in order to know how many pieces of media you should have. For example, if
your backup normally takes three pieces of media—and you want two sets of this media—you should
have six pieces of media.
NOTE:
When a rotation is written to media and needs to know the set number it should use for the media's name
it pulls this information from the Next set to use field in the interval. If a backup failed to run correctly
or if for some reason the set numbers are now out of sync you can use this value to change the name
used the next time that interval is run.

Selecting a Rotation Type

Besides the No media rotation option, Data Protector Express provides several default media rotation
types. The rotation types vary in several ways: the number of days for which full data recovery is
available, access to historical files based on backup type (full, differential, incremental, etc.), the minimum
number of tapes or other media needed, and how long media is retained.
Full data recovery period
All the media rotation types provide for full data recovery in case of disaster. The full data recovery
period is the number of days prior to the data loss for which every file backed up can be recovered. You
will also be able to reconstruct the data for any day during that period that you ran a full backup and for
which a set is available that has not been reused.
Each media rotation type provides full data recovery periods for different number of days preceding the
last backup. For example, a GFS 30-tape media rotation type can reconstruct the data from any day
of the past three weeks (except weekends), while a Simple 4-tape media rotation type provides for
reconstruction of only the past two days.
An example of an hourly media set is "9 :00 PM Hour." An example of a daily
Fixed by week of month. An example of an hourly media set is "9:00 PM
An example of an hourly media set is "9:00 PM Hour." An example of a daily
An example of an hourly media set is "9:00 PM Hour." An example of a daily
User's Guide and Technical Reference
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