To view the status and storage information of the local disk on your FortiGate unit, go to System > Advanced. The DiskSettings menu appears only on FortiGate units with an internal hard or flash disk.
Formatting the disk
The internal disk of the FortiGate unit (if available) can be formatted by going to System > Advanced and selecting Disk Settings.
Formatting the disk will erase all data on it, including databases for antivirus and IPS; logs, quarantine files, and WAN optimization caches. The FortiGate unit requires a reboot once the disk has been formatted.
Setting space quotas
If the FortiGate unit has an internal hard or flash disk, you can allocate the space on the disk for specific logging and archiving, and WAN optimization. By default, the space is used on an as required basis. As such, a disk can fill up with basic disk logging, leaving less potential space for quarantine.
By going to System > Advanced, you can select the Edit icon for Logging and Archiving and WAN Optimization & Web Cache and define the amount of space each log, archive and WAN optimization has on the disk.