Migrating to a new FG cluster with a large number of FSW

[simonorch]

We can't find anything in docs or kb on this and what i'm reading on redit is scary.

when migrating a FG cluser to new boxes and you have managed FSW (24 spread across 3 DCs in our case). Do you really have to factory reset them all to get them up on the new cluster?  

Deauthorizing them i guess is fair enough, but factory reset??

gates are on 6.4.7 and switches on 7.0.2

I tested this in a lab with a couple of small switches and a reset was the only way i could get them up on the new FG so i fear the worst but i hope i'm missing something.

[Troubleshooter_73]

What are the old and new Fortigate Models? I would assume you can use FortiConverter Service to convert the whole FortiOS configuration from the old to the new cluster primaries and after that, everything should be back in balance. I'm not sure, but an authorized switch is only an entry in the configuration or isn't it?