On Tue, Mar 25, 2014 at 12:22 PM, Joshua D. Drake <jd@xxxxxxxxxxxxxxxxx> wrote: > On 03/25/2014 08:18 AM, Ilya Kosmodemiansky wrote: >> >> >> Joshua, >> >> that is really good point: an alternative is to use pg_basebackup >> through ssh tunnel with compression, but rsync is much simpler. > > > Or rsync over ssh. The advantage is that you can create backups that don't > have to be restored, just started. You can also use the differential > portions of rsync to do it multiple times a day without much issue. rsync's delta transfer isn't relly very effective with postgres. You don't save any I/O, just network traffic, and in general the bottleneck is I/O (unless you have a monster I/O subsys or a snail of a network one). There were some musing about making delta transfer more efficient in pg in hackers, but I don't think anything tangible came out of that, so it's basically equivalent to a full transfer. The only reason to leverage rsync's delta transfer would be to decrease the time between pg_start_backup and pg_stop_backup, which could only matter if you're low on WAL space, but the reduction, in my experience, isn't stellar. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
