Knowledgebase: Index related
Calculating the size of backup indices
Posted by Sven Koester, Last modified by Sven Koester on 07 October 2008 8:08
Organisation basics |
PresSTORE maintains for each file in the backup the tape it is stored on and the time stamp of that file. This storage is done in the backup index.
The backup index consists of multiple file sets, each one holding the data for one backup cycle.
The files where the backup index data is stored in subdirectories below the PresSTORE home directory.
The index data is kept as long as files from the according cycle can be recovered from the tape, that is, as long as the tape exists. The index data file is kept as long as there exists as least one volume of that index cycle.
Calculating the backup index size
An index entry requires approximately 1 KB of data. Example:
For 100.000 files over 4 backup cycles, the total amount of space is approximately 100000 * 4 * 1 KB = 400 MB.
The number of 100.000 files represents approximately "all files of a workstation computer".
Note that the index size depends on the number of files, not on the amount of data.
To figure out, how many files are on the disk, execute the following command from a terminal window in the root directory of the volume to be backed up
On Mac, Linux and Solaris:
ls -R | wc -l
On Windows (regard the last two output lines):