Re: pg_upgrade and rsync

* Andres Freund (andres@2ndquadrant.com) wrote:
> On 2015-01-23 14:27:51 -0500, Stephen Frost wrote:
> > * Andres Freund (andres@2ndquadrant.com) wrote:
> > > On 2015-01-23 14:05:10 -0500, Stephen Frost wrote:
> > > > If I follow what you're suggesting, pg_upgrade would
> > > > need a new 'in-place' mode that removes all of the catalog tables from
> > > > the old cluster and puts the new catalog tables into place and leaves
> > > > everything else alone.
> > >
> > > No. Except that it'd preserve the relfilenodes (i.e. the filenames of
> > > relations) it'd work exactly the same as today. The standby is simply
> > > updated by rsyncing the new data directory of the primary to the
> > > standby.
> >
> > You'd have to replace the existing data directory on the master to do
> > that, which pg_upgrade was designed specifically to not do, in case
> > things went poorly.
>
> Why? Just rsync the new data directory onto the old directory on the
> standbys. That's fine and simple.

That still doesn't address the need to use --size-only, it would just
mean that you don't need to use -H.  If anything the -H part is the
aspect which worries me the least about this approach.
Thanks,
    Stephen