Reload has a Simple Scenario Disk Sizing Calculator. You can find it at http://reload.gwava.com/post_office_size.htm.

When deploying Reload as a hot backup solution for GroupWise, proper disk storage planning is key.

Reload differs from a traditional backup solution in the fact that its data is always live, ready to be accessed at a moments notice. Unlike tapes which are loaded and restored, Reload stores backed up data as "hot backups" on the Reload server's disk drive. Reload is designed to hold several weeks worth of GroupWise content. The number of weeks of backup is decided by the GroupWise administrator. Before deploying Reload, a GroupWise administrator decides how many weeks of content is needed, checks the size of their GroupWise Post Offices, and then performs a simply calculation to know how much disk space Reload will require.

The math is Size of Post Offices multiplied by the number of weeks multiplied by 2.5.

You can find the Simple Scenario Disk Sizing Calculator at http://reload.gwava.com/post_office_size.htm