HP Data Protector Software Cell Manager Planning and Sizing

Specifics for large cells
If the number of files grows into the tens of millions, or there are tens of thousands of files generated
on a daily basis, and you use the Log All option, then backup speed and IDB growth will become a
problem in a relatively short period of time.
In this situation, you have the following options:
• Reduce the logging level to the smallest acceptable level. Setting the Log Files option can reduce the
IDB size to a third, and setting the Log Directories option to almost a tenth. This, of course, depends
on the nature of the file systems in the cell.
• Reduce the catalog protection to a minimum.
• Split the cell in two. As a final solution, you can always introduce another IDB and redirect half of
the systems into it.
You can configure report on system dynamics, which informs you about dynamics of the growth of
filenames on a particular client.
Maintenance of DCBF directories
The IDB allows several directories to be registered where DC binary files are stored. The purpose of
this is to allow the binary files to be distributed over more disks/filesystems. By default, there is only
one directory: ../db40/dcbf
Each DCBF directory has several configuration attributes. Those are:
MaxSize: specifies what amount of disk space can be used for DCBF in this directory. When this size
is reached, new DCBF files will not be created any more.
MaxFiles: specifies how many DCBF files can be stored in the directory.
SpaceLow: Low disk space required before an additional DCBF file can be created.
Whenever there is a need to create a new binary file, the “DCBF allocation procedure” needs to be
performed by Data Protector.
First, from the list of all possible DCBF directories, Data Protector will eliminate all that are de-activated or
missing. Note that in the case of missing DCBF directory, an OBDB_Corrupt event will be generated.
Then, all full DCBF directories will be not considered. DCBF directory is considered full if at least one
of the following conditions is true:
MaxSize-CurrentSize<SpaceLow
DiskSpace<SpaceLow
MaxFiles<=CurrentFiles
Then a set of user selectable algorithms will select the actual DCBF directory (global option per cell).
1. Fill in sequence
HP Data Protector always tries to create the new DCBF file in the first DCBF directory according to
the sequence.
2. Balance size
HP Data Protector will select the DCBF directory that contains (proportionally to size limit) the least
DCBF file size. Minimum for the following value is selected:
(MaxSize-CurrentSize-SpaceLow)/(MaximumSize-SpaceLow)
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