On Wed, Jan 13, 2010 at 8:36 PM, Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> wrote: > Our documentation suggests that you can take a base backup of a warm > standby server while it's running: > >> If we take a backup of the standby server's data directory while it is >> processing logs shipped from the primary, we will be able to reload that >> data and restart the standby's recovery process from the last restart point. >> We no longer need to keep WAL files from before the restart point. If we >> need to recover, it will be faster to recover from the incrementally updated >> backup than from the original base backup. > > That doesn't seem safe. If the server makes a new restartpoint while the > backup is running, and pg_control is backed up after the new > restartpoint is made, recovery will restart from the new restartpoint. > That is wrong; recovery needs to restart at the restartpoint that was > most recent when the backup started. This is basically the same issue we > have solved in master with the backup_label file.
Right. > I wonder if it would be enough to document that pg_control must be > backed up first? Probably No. The archive recovery from such base backup would always fail at the end of recovery because there is no backup-end record, i.e., pg_stop_backup() is not executed in that case. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers