It is important to plan for your SharePoint environment carefully before starting implementation. Many companies opt for a small or medium size farms (3 to 6 servers in the farm), but they need to make this decision based on a capacity planning exercise (Use the farm size guidelines at http://technet.microsoft.com/en-us/library/ff758647.aspx to determine the size farm appropriate to your organization).
Larger enterprises with large user base would generally opt for large size farms, so they need to do a more rigorous capacity planning exercise to select their initial deployment configuration.
It is important to note that Capacity Planning for SharePoint is part of a larger process for capacity management. Due to the nature of SharePoint, the data sizes and usage can get much higher than initially anticipated. For example, departments may decide to move more content into SharePoint than initially estimated, users may use My Sites heavily and demand even more quota for their sites, or custom built applications for some line of business applications may increase the usage of the SharePoint environment.
Thus, the SharePoint environment needs to be monitored carefully to identify any bottlenecks and remedy them quickly. Such issues are generally resolved by scaling-up or scaling-out. Scaling-up means adding more processing power, RAM, or disk to the current servers to cater for the load. Scaling-out means adding more servers to the SharePoint farm.
The general approach for capacity management in SharePoin is detailed at http://technet.microsoft.com/en-us/library/ff758647.aspx and it includes the following steps:
In the next posts, I’ll draft the approach for sizing of SharePoint 2010 and its different service applications. The approach will include the different decisions made and the reasoning behind them.