Technical Tip: How to rebuild the FFDB database in case of error 'ffdb_err_msg_print: ret=-4, Error: kernel error'

[nverma]

Description	This article describes how to rebuild the FFDB database in case of error 'ffdb_err_msg_print: ret=-4, Error: kernel error'.
Scope	FortiGate v7.0 or later.
Solution	Kernel error 'ffdb_err_msg_print: ret=-4, Error: kernel error' is observed on the FortiGate when there is an issue with the FFDB files. This can be verified using the below command: diagnose debug config-error-log read It is possible to remove the FFDB files using the below steps and download the database again. To clear the FFDB files: diag internet-service clear /data2/ffdb_app diag internet-service clear /data2/ffdb_map diag internet-service clear /data2/ffdb_map_res Use the command 'fnsysctl ls /data2/' to verify the database is deleted. Run the below command to download the database again: execute update-now For the FortiGate Cluster, the Kernel error 'ffdb_err_msg_print: ret=-4, Error: kernel error' may cause out-of-sync issue between the FortiGates' devices. If the above troubleshooting steps did not help, fail-over the traffic to one of the FortiGates that has no error and consider rebooting the FortiGates with the error detected.