I'm migrating to a new server. I've backed up virtualmin which creates about 15GB of files (99% mail).
On the new server, I go to 'restore backup', point it at the backup files directory and press the button at the bottom of the page 'show what will be restored'.
At this point, top shows CPU activity, mainly gzip for a few minutes but once that stops, the web interface doesn't refresh - I suspect perhaps a timeout.
By the way I'm backing up from virtualmin 3.87 and restoring to 3.92, is this likely to be an issue? Upgrading the old server is sometimes an issue as the operating system is too old to support modern versions of dependencies like python due to libc version differences.