I would liketo know the relationship among local-only device , primary device and secondary device .

[choyilwin]

The local-only option allows you to upgrade only the local device.The secondary-only option allows you to upgrade the secondary members,but the primary FortiGate will not be upgraded.

[Carson_Daniels]

The local-only device upgrade affects only that specific device. The secondary-only upgrade updates secondary devices, leaving the primary FortiGate unchanged. Understanding this helps prevent accidental upgrades on critical units.