From: Stephen Frost <sfrost@snowman.net>
To: Ayush Goyal <ayush@helpshift.com>
Cc: pgsql-admin@postgresql.org
Subject: Re: Using pg hotbackup directly without wal archives
Date: Wed, 26 Oct 2016 09:30:56 -0400
Message-ID: <20161026133056.GB13284@tamriel.snowman.net> (raw)
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Greetings,
* Ayush Goyal (ayush@helpshift.com) wrote:
> I need to ask if there is a way to use the pg hot backup taken via
> pg_start_backup() and pg_stop_backup() calls directly without using the wal
> archives.
No, WAL is required for correct backups. There are multiple ways to
ensure that the WAL is archived.
> If I start postgres with just base backup without setting up recovery.conf
> for fetching archived wal logs, I get this im the log files:
>
> 2016-10-26 06:48:25 UTC LOG: database system was shut down in recovery at
> 2016-10-25 15:50:16 UTC
> 2016-10-26 06:48:25 UTC LOG: invalid primary checkpoint record
> 2016-10-26 06:48:25 UTC LOG: invalid secondary checkpoint record
> 2016-10-26 06:48:25 UTC PANIC: could not locate a valid checkpoint record
> 2016-10-26 06:48:25 UTC LOG: startup process (PID 980) was terminated by
> signal 6: Aborted
> 2016-10-26 06:48:25 UTC LOG: aborting startup due to startup process
> failure
>
> Also, I noticed that if I run pg_resetxlog, I am able to start postgres,
> but I am not sure if the database is consistent after running
> pg_resetxlog. Is database state consistent after running pg_resetxlog on
> this hot backup?
No, the database state will *not* be consistent after pg_resetxlog. You
must archive the WAL which is written during the backup and must provide
a recovery.conf when performing a restore.
I strongly recommend that you look at using the existing PG backup tools
which will correctly perform the backup and WAL archiving, such as
pg_basebackup, pgBackRest, or barman.
Thanks!
Stephen
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To: pgsql-admin@postgresql.org
Cc: sfrost@snowman.net, ayush@helpshift.com
Subject: Re: Using pg hotbackup directly without wal archives
In-Reply-To: <20161026133056.GB13284@tamriel.snowman.net>
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