Sun Java System Calendar Server 6 2005Q4 Administration Guide

Simple Sizing Exercise

The following are a few rough formulas based on a medium usage profile for figuring how many back-end and front-end servers you need, and how much storage:

Definition of Medium Usage Profile

For our rough estimates, we are assuming the following:

Number of Front-End CPU's

The formula is:

Number of CPU's = Number of Concurrent Users divided by 4800

Number of Back-End CPU's

The formula is:

Number of CPU's = 4 CPU's per 500,000 configured users

Amount of Storage Needed

The formula is:

Amount of Storage = 5 emails per week times 52 weeks a year times 2K per email (5*52*2K)

= 520KB per user per year

For the assumed two years of calendar data, 1 MB per user.