Migrate existing GVM installation to a new host system

Yes, there are known issues with CentOS7, they have working in CentOS8 and suggest as a workaround. Could someone here give some pointers on how to transfer the data? I’d like to keep the previous work if possible. Also, instead of putting on CentOS8, would you recommend Ubuntu or even FreeBSD? I love both and looks like they have packages if anyone has had good luck with either.