Chapter 19 Virtual Domains : Troubleshooting Virtual Domains : FortiGate unit running very slowly
  
FortiGate unit running very slowly
You may experience a number of problems resulting from your FortiGate unit being overloaded. These problems may appear as:
CPU and memory threshold limits exceeded on a continual basis
AV failopen happening on a regular basis
dropped traffic or sessions due to lack of resources
These problems are caused by a lack of system resources. There are a number of possible reasons for this.