If the postmaster is stopped with 'pg_ctl stop' while an online backup is in progress, the 'backup_label' file will remain in the data directory.
There is no recovery.conf file present. When the server is started again, it attempts to recover from the checkpoint marked in the backup_label file even if the shutdown was clean. If the WAL file mentioned in backup_label is not in pg_xlog (it has already been archived and removed because there was enough database activity since pg_start_backup()), the startup process will fail with a message like this: LOG: could not open file "pg_xlog/000000020000000000000084" (log file 0, segment 132): No such file or directory LOG: invalid checkpoint record PANIC: could not locate required checkpoint record HINT: If you are not restoring from a backup, try removing the file "/POSTGRES/data/PG820/backup_label". My question: Is it safe to just delete the file as the hint suggests? I see the following comment in src/backend/access/transam/xlog.c: /* * read_backup_label: check to see if a backup_label file is present * * If we see a backup_label during recovery, we assume that we are recovering * from a backup dump file, and we therefore roll forward from the checkpoint * identified by the label file, NOT what pg_control says. This avoids the * problem that pg_control might have been archived one or more checkpoints * later than the start of the dump, and so if we rely on it as the start * point, we will fail to restore a consistent database state. "We will fail to restore a consistent database state" sounds rather intimidating. *If* - on the other hand - it is safe to follow the hint and remove the backup_label, wouldn't it be a good thing for the startup process to ignore (and rename) the backup_label file if no recovery.conf is present? Or, alternatively, the backup_label file could by removed by a clean shutdown. Thanks, Laurenz Albe ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq