On 10/25/21 13:13, Stephen Frost wrote:
No, it's not- you must also be sure to archive any WAL that's generated between the pg_start_backup and pg_stop_backup and then to be sure and add into the snapshot the appropriate signal files or recovery.conf, depending on PG version, to indicate that you're restoring from a backup and make sure that the WAL is made available via restore_command. Just doing stat/stop backup is*not* enough and you run the risk of having an invalid backup or corruption when you restore. If the entire system is on a single volume then you could possibly just take a snapshot of it (without any start/stop backup stuff) but it's very risky to do that and then try to do PITR with it because we don't know where consistency is reached in such a case (we*must* play all the way through to the end of the WAL which existed at the time of the snapshot in order to reach consistency). In the end though, really, it's much, much, much better to use a proper backup and archiving tool that's written specifically for PG than to try and roll your own, using snapshots or not. Thanks, Stephen
Stephen, thank you for correcting me. You, of course, are right. I have erroneously thought that backup of WAL logs is implied because I always back that up. And yes, that needs to be made clear.
Regards -- Mladen Gogala Database Consultant Tel: (347) 321-1217 https://dbwhisperer.wordpress.com
