Troubleshooting Tip: Unable to restore configuration with error 'failed to restore system configuration'

This issue commonly occurs with small-scale FortiGate models such as the 30, 40, and 50 Series due to their limited capacity.

When restoring the configuration from the GUI, the following warning may appear:

To work around this issue, first check the following:

1) Storage capacity. Run the following command in the FortiGate CLI (example output is provided below):

# fnsysctl df -h
Filesystem Size Used Available Use% Mounted on
rootfs 504.3M 69.0M 435.2M 14% /
tmpfs 504.3M 69.0M 435.2M 14% /
none 656.2M 71.3M 584.8M 11% /tmp
none 656.2M 536.0K 655.7M 0% /dev/shm
none 656.2M 19.6M 636.5M 3% /dev/cmdb
/dev/mtd6 18.0M 17.7M 244.0K 99% /data <-- running out of capacity 
/dev/mtd7 30.0M 28.5M 1.4M 95% /data2

2) IPS global settings:

# show ips global
config ips global
set database regular  -->set to regular 
end

3. Antivirus settings:

# show antivirus settings
config antivirus settings
set default-db normal -->set to normal

end 

Next, take the following steps:

1) Disable autoupdate:

#config sys autoupdate schedule
set status disable
end

2) Delete the geo-ip database. The FortiGate will reboot after the operation is confirmed.

# diagnose geoip delete-geoip-db     

After rebooting, the FortiGate will have more space available.

# fnsysctl df -h
Filesystem Size Used Available Use% Mounted on
--truncated--
/dev/mtd6 18.0M 17.7M 244.0K 84% /data <-- more space has been made available
/dev/mtd7 30.0M 28.5M 1.4M 84% /data2

Try restoring the configuration again. If the issue persists, contact Fortinet TAC.

Related documentation:

Technical Tip: How to save and restore configurati... - Fortinet Community