Is that possible to build a secondary server who is the copy of my principal server who will answer if the principal doesn’t answer. If it’s possible, how will I set the secondary server to be up to date when I update the principal server?
Yes, when setting up a High Availability Environment with VitalPBX, one of the requirements is that both servers are equal. This would spec-wise, same CPU, Memory, Storage, and also same licensing. So if you have the Main Server with a Carrier Licensing Plan, for example, your Secondary Server must also have its own Carrier Licensing Plan.
With version 3 of VitalPBX, thanks to MariaDB 10 that comes with a Galera, it will be much easier to make High Availability. We have already done tests with very good results and we hope to publish the post when we release version 3 of VitalPBX.
And the answer is YES, it is necessary to have a license for each server.