FortiGate models with 2 GB RAM cannot be a Security Fabric root

A Security Fabric topology is a tree topology consisting of a FortiGate root device and downstream devices within the mid-tier part of the tree or downstream (leaf) devices at the lowest point of the tree.

As part of improvements to reducing memory usage on FortiGate models with 2 GB RAM, this version of FortiOS no longer allows these models to be the root of the Security Fabric topology or any mid-tier part of the topology. Therefore, FortiGate models with 2 GB RAM can only be a downstream device in a Security Fabric or a standalone device.

The affected models are the FortiGate 40F, 60E, 60F, 80E, and 90E series devices and their variants.

FortiGate models with 2 GB RAM running FortiOS 7.4.2 or later can be used as the Security Fabric root. See FortiGate models with 2 GB RAM can be a Security Fabric root.

To confirm if your FortiGate model has 2 GB RAM, enter diagnose hardware sysinfo conserve in the CLI and check that the total RAM value is below 2000 MB (1000 MB = 1 GB).

In the GUI on the Security Fabric > Fabric Connectors page when editing the Security Fabric Setup card, the Security Fabric role can only be configured as Standalone or Join Existing Fabric.

In the CLI, the following error messages are displayed when attempting to configure a FortiGate model with 2 GB RAM as a Security Fabric root:

config system csf
    set status enable
end

...
 
2GB-RAM models cannot be a Security Fabric root.
Please set the upstream.
object set operator error, -39, roll back the setting
Command fail. Return code -39