HP B6960-96035 - Manual (Page 150)

concurrently written in sess_7 and the second one in sess_8. Note that one object
can be stretched over several media. The media usage policy is appendable.
Figure 44 Each object written on a separate medium
Figure 44 on page 150 shows an example of using one backup specification per
object with the non-appendable media usage policy. The result is higher media
consumption. You could combine this with the append incrementals only policy, to
get the incremental backups of the object on the same medium.
For more information on how full and incremental backup policies influence restore
performance and media usage, see “
Full and incremental backups ” on page 71.
Writing data to several media sets during backup
During a backup session, you can write all or some objects to several media sets
simultaneously, using the Data Protector object mirror functionality. For more
information, see “
Object mirroring ” on page 119.
Calculating media condition
Media condition factors
Data Protector calculates the state of used media using media condition factors. The
state of the poorest medium in a pool determines the state of the entire pool. For
example, as soon as the state of one medium in a media pool is poor, the state of
the pool becomes poor. When that particular medium is removed from the pool, the
state reverts to either fair or good.
Media can have three states: good, fair, or poor.
On a per medium basis, the following is used for calculating the condition:
• number of overwrites
The usage of a medium is defined as the number of overwrites from the beginning
of the medium. Once the medium has more than the threshold number of
overwrites, it is marked as poor
Media management and devices 150