On Wed, Oct 7, 2015 at 15:38, David G. Johnston <david.g.johnston@xxxxxxxxx> wrote:
Thank you very much. I read someplace if you run pg_start_backup twice the backup.old will be created, but there was not much beyond that and now I can't seem to find the reference.
backup_label gets deleted on pg_stop_backup() on the *master*.
Backup_label will still be in the *backup* itself however (or, more succinctly, a slave server). When you start the backup / slave, it will process backup_label so that it can start recovery. Once we don't need it anymore, the file is renamed to backup_label.old. Typically, when you see a backup_label.old on a writable master, it was either:
* a backup that was restored and put in to service
* a slave server that was promoted
A pg_controldata will probably show a timeline != 1
Scanning the docs and logic tells me that attempting to do pg_start_backup twice in a row should result in the second attempt giving an error...but I could be misinformed.The file pg_start_backup creates is named "backup_label" and so I'd also expect any attempt to add an old suffix would keep the same base name...David J.
