Create new V20 install from old V18 backup?

[PBX_Programmer]

We've inherited a customer who's got an old V18 on premises system which is too old to automatically upgrade to V20. The license has expired and it turns out that it was only ever running on a trial license. It is not possible for the existing setup to reach out to licensing servers because the server it's trying to reach doesn't exist any more, as I understand it.

We have purchased a new Pro license for it (on the portal it shows as a V18 Pro license for 8SC). The plan was to build a new on-premises system from scratch using the V20 ISO, license it with the new license we've purchased and then install a backup from the old V18 system. Or if necessary do it the other way, install from the V20 ISO, install the V18 backup and then apply the new license. I'm not sure at this stage whether the V18 backup we use should or shouldn't contain the license and FQDN information.

Is that going to work? Is there a better way of doing it? If possible, we want to avoid having to program the whole system from scratch and were therefore looking to apply the V18 backup to it, containing all the config.

Any guidance would be appreciated, please.

Thanks!

 

[bitn2]

Depends how old your v18 is. But when you are not on v18 9a (31), your backup will not work on v20. So you need to start from scratch.

 

[NicholasP_3CX]

In order for a Version 18 backup to work on Version 20, it must be a Version 18 Update 9 backup.

You would need to load it up on a V18U9a installer, assign a System Owner (with a unique email address) and then replace the key with the new one you have purchased.

Then you can perform the migration to a Version 20.

It might be easier just to export the users, perform a clean install, import the users and setup the rest of the system.

Either way, this will take some time to bring the customer up to spec.