WAN optimization uses disk storage for byte caching (see “Byte caching”). Web caching uses disk storage to cache HTML pages, images, servlet responses and other web-based objects for later retrieval.

You can also go to System > Config > Advanced > Disk Management to view the storage locations on the FortiGate unit hard disks and to change the amount of disk space available for WAN optimization and web caching.

You can also view information about disk storage using the config wanopt storage command.

Normally you do not have to change storage settings. However, you can reduce or increase the amount of disk space used for WAN optimization and web caching.