We are planing a migration from old 8.04LTS to new 12.04LTS virtual Xen servers (on top of a brand new 12.04LTS cluster system). We are looking at 2 variants:
1) we could basically clone the sites like described here: https://www.virtualmin.com/documentation/system/migrate
AND also clone the Webmin/Virtualmin/Usermin's own configurations completely (except the base system's IP address in the first testing step, but then also that one too).
1a) What's the best way to clone all of the VIrtualmin's configurations (except hostname and host IP address) ?
During the process, we will first setup new IP address for the new system to perform tests, then shutdown the old system (actually unsync it from DNS servers, and reassign a new IP address to it) and then test test test, and then clone completely the configuration, including the IP address of the old system (the systems are virtual Xen instances so that's not an issue).
We also have DNS links to secondary DNS and secondary mail servers managed by virtualmin, which are also being migrated, and would like to keep the DNS primary-secondary links in that process (but in the second migration step, once tests are done).
1b) how should we handle the DNS secondary servers migration ?
What's the best way to achieve this ? I haven't found it in the Virtualmin documentation, maybe I missed something ?
2) Alternatively, if that would be considered simpler, we could move with dd the old Xen instances (Xen using LVM-virtual disks on the old system) to the new system (Xen using files-based virtual disks), and then dist-upgrade them from 8.04LTS to 12.04LTS,
2a) but then we would probably not be able to boot them in 8.04LTS on the new 12.04LTS systems as the 12.04LTS release does not have the 8.04LTS kernels in it that are used by XEN (?). Also a dist-upgrade from 8.04LTS through 10.04LTS to 12.04LTS might also bring its lot of surprises, compared to backup-and-restore of the sites and of the Webmin/Virtualmin/Usermin configurations.
2b) Any recommendations for that possibility ?
3) Finally, globally any recommendations for best way to migrate all those web+mail servers as well as the secondary DNS servers (primary DNS servers are on the webhosts) between method 1) and 2) above ?
Thanks for your help and insight and Best Regards, Beat