On Tue, Feb 08, 2022 at 08:32:22AM +0000, Victor Sudakov wrote: > Julien Rouhaud wrote: > > > > > pg_basebackup takes time for large databases (> 5TB). I feel rsync should > > > be faster. > > > > Not necessarily. pg_basebackup will do simple sequential read of all the data, > > which is probably the fastest thing to do. rsync will do some extra processing > > that isn't required in that scenario, so it's likely to be slower (although > > probably only marginally slower). > > I think Nikhil was going to invoke the rsync black magic as described > in https://www.postgresql.org/docs/current/pgupgrade.html, not for > copying the entire PGDATA from the master to standbys. While the rsync > magic should be hundreds of times faster because only modified files > will be copied and the majority of files will be just hardlinked, I've > never felt I have enough skill and luck to undertake this method. Ah, if that's the case I don't think there's any doubt to have for rsync being faster. And this method works just fine if you take care of what you're doing.
