%BOOK_ENTITIES; ]> This chapter outlines best practices for planning the required and/or desired capacity. Please note that the numbers here are illustrative, and based on a large number of assumptions. Making the assumptions is not as bad as it sounds; not recognizing the assumptions made to draw a conclusion from the result is far worse. Many things relate to capacity planning, including but not limited to; User & usage profiles, Total, concurrent number of users, Duration of, and percentage of workload pushed through during, the peak usage period, Number of emails with attachments, type of emails, average sizes, traffic flows, Corporate policies, local regulations, High-availability requirements, Use of Quotas In this illustrative scenario, the user and usage profiles listed in are used for capacity planning. The user profiles do not necessarily represent any given environment accurately. If you have statistics available, you should use those instead to classify and quantify your users. Profile Percentage TODO: percentage of what? Receives Sends Reads Deletes Logins Light 25% 20 5 20 10 2 Medium 55% 40 10 40 20 2 Heavy 10% 80 20 80 40 2 Very Heavy 10% 120 30 120 60 2 Additionally, the parameters listed in are used to make the calculations for this illustrative scenario. Title Value Units Description / Remark Number of Users 1,000,000 Average Mail Size 50 KB Quota 1024 MB Webmail Polling Interval 300 seconds Polling Cost (Incoming) 1 KB Polling Cost (Outgoing) 1 KB Users Logged In 10 % Users Interacting 5 % Interaction Factor 4 How often does the webmail user interact with the interface, per minute, when considered "actively interacting"? This is the number of *additional* hits per minute Interaction Cost 4 KB Cost of a single interaction hit Hours / day 10 h Number of hours per day, users are considered to be working. Duration of peak period 120 The duration of the day's peak usage, in minutes Kolab Systems can provide you with assistance and full capacity planning customized to your environment and requirements. For more information, please contact sales@kolabsys.com.