If your company deploys applications that use HTTP Federation (HFED) Proxy, you must calculate how much disk space to allocate for storing user profiles (keychains) in backup locations.
Before you calculate storage for backups, you need to calculate storage for user profiles on the identity router.
Assume that you are calculating for a cluster of one or more identity routers that use a common backup location. Calculate the amount of base storage needed for user profiles, and then calculate the backup space.
To calculate the base storage requirement for user profiles, use the following formula:
(Number of users) x (Number of applications) x 6 KB = Base Storage Required
If you want to add disaster recovery sites, double the base storage requirement.
Use this formula to calculate the amount of space needed to store backup files:
(Base storage requirement) x (Number of backups you intend to keep) = Backup Disk Space Required
For example, suppose the base storage requirement is 3 MB and you are keeping five backups. The calculation is 3 MB x 5 = 15 MB disk space required for backups.