360Plus backup repository size calculation

Introduction

This document explains how to estimate the size of the 360Plus backup repository.
The retrieved information comes from performance tests ran in our Dev labs and customers environment.
The numbers may change depending on SAP BusinessObjects version and database engine.

360Plus backup repository size at first run

Before starting, we can say that the backup repository size mainly depends on SAP BusinessObjects FRS size.

Basic Objects (No FRS input)

A basic object (user, user group, public folder...) without FRS input takes around 2Kb
That is less than the minimum amount of space required by the operating system to save a file (Size on disk).


Assuming the SAP BusinessObjects has 150000 users in 50000 groups, it will represent 800000Kb (800Mb).
That small size is explained by the fact that all those basic objects are represented by a few database columns converted in a XML file.

Complex objects (FRS input)

Running our performance tests helped us figure out that there's a difference between the two FRS storages (Input and Output).
The BIAR compression is more efficient on the Input FRS than on the Output FRS as you can see in the results below:


FRS Size
Backup repository size
Compressed size %
Input
187Mb
44Mb
23.52%
Output
224Mb
156Mb
69.64%

Formula

Backup repository size estimation (Mb) = Input FRS size (Mb) * 0.24 + Output FRS size (Mb) * 0.70 + Number of basic objects * 0.002
(*1)

360Plus backup repository size after multiple backups

As we know, the backup engine only backs up the objects that have been modified or added after the last run. This is known as a delta or incremental process.
This mechanism implies that the backup repository size highly depends on the SAP BusinessObjects objects' update and growth rates between two runs of a backup task.
Those rates will be different for any customer we have and can not be easily calculated.

At worst, on an inactive FRS (no objects added), the size of the 360Plus backup repository can reach the following: (Input FRS size (Mb) * 0.24 + Output FRS size (Mb) * 0.70 + Number of basic objects * 0.002) * Configured maximum number of backups
(*1)
This formula means that after a long period of recurring backup tasks, all the objects of the SAP BusinessObjects have been backed up at most the number maximum number of backups times.
This formula does not consider the growth rate. This rate cannot be estimated or is not valid for all the customers.

*1 : The formula is based on multiple test in our labs. It may evolve depending on customer feedback.

Last updated about 4 years ago