HP Data Protector Software Cell Manager Planning and Sizing

Recommended usage of logging level and catalog protection
Always set a reasonable level of catalog protection. The only exception is if the Log None option is
set (in this case, catalog protection does not apply anyway).
If you set the catalog protection to Permanent, the information in the IDB is removed only when media
are exported or sessions are deleted. In this case, the size of the IDB grows linearly until the data
protection period is reached, even if the number of files in the cell does not change. For example, if
the data protection period is one year and media are recycled, then significant growth of the IDB
stops after one year. The addition of new catalogs is approximately equal to the removal of old ones.
If catalog protection is set for four weeks, significant growth of the IDB stops after four weeks.
Therefore, in this case, the IDB is 13 times larger if the catalog protection is set to one year.
It is recommended that catalog protection includes at least the last full backup. For example, you can
set a catalog protection of eight weeks for full backups and one week for incremental backups.
Use different logging levels in the same cell
A cell often consists of mail (or similar) servers that generate a large number of files on a daily basis,
database servers that store all information in a handful of files, and some user workstations. Since the
dynamics of these systems are rather different, it is very difficult to prescribe one setting that suits them
all. Therefore, it is recommended to create several backup specifications with the following logging
level settings:
• For database servers, no logging is necessary as they have their own restore policies. Therefore,
use the No Log option.
• For workstations/file servers, the Log All or Log Files options allow for searching and restoring
different versions of files. For backups with the Log Directories or No Log options set, you can import
catalogs from the media, which, in a reasonably short time, allows the possibility to browse for the
selected object. For information on importing catalogs from media, refer to online help, index
keyword “importing, catalogs from media.”
Different logging levels for ObjectCopies
Backed up objects and object copies or mirrors of these objects can have the same or different
logging levels. Depending on your backup policy, the selected logging level of object copies can be
more or less detailed than that of the source objects.
For example, you can specify the No Log option for object mirrors if you create these mirrors just to
provide a successful completion of a backup session. Or, you can specify the No Log option for a
backup object to increase the backup performance, and then specify the Log All option for this object
in a subsequent object copy session.
Specifics for small cells
If the number of files in a cell is small and will remain small (a million files or less) and the systems
in the cell perform usual business activities, you can always use the Log All option, which is the
Data Protector default. However, you need to take care of IDB growth and set a reasonable level of
catalog protection.
25