On Sun, Aug 21, 2016 at 1:24 PM, Craig Ringer <craig.ringer@2ndquadrant.com> wrote: > On 21 Aug 2016 12:36 AM, "Bruce Momjian" <bruce@momjian.us> wrote: >> Seems like another good idea to use pg_basebackup rather than manually >> doing base backups; Magnus has been saying this for a while. > > The main time that's an issue is when you're rsync'ing to save bandwidth, > using CoW volume snapshots, etc. pg_basebackup becomes totally impractical > on big systems.
Yes, and that's not fun. Particularly when the backup takes so long that WAL has already been recycled... Replication slots help here but the partitions dedicated to pg_xlog have their limit as well.
We can and probably should allow XLogReader to invoke restore_command to fetch WAL, read it, and discard/recycle it again. This would greatly alleviate the pain of indefinite xlog retention.
It's a pain to do so while recovery.conf is its own separate magic though, not part of postgresql.conf.
