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help / color / mirror / Atom feedFrom: Ron Johnson <[email protected]>
To: PostgreSQL General <[email protected]>
Subject: Re: Backups with filesystem snapshots
Date: Mon, 11 Aug 2025 09:13:38 -0400
Message-ID: <CANzqJaBG3yn7-BCgjDuUWqusKSBSsCwk1Lw+vSe26EZQRfMtXw@mail.gmail.com> (raw)
In-Reply-To: <CAFgz3ksJNVprBWLX4x=MdfJrG+uZSgUHTYGF35T=dJryJjz8zw@mail.gmail.com>
References: <CAFgz3ksJNVprBWLX4x=MdfJrG+uZSgUHTYGF35T=dJryJjz8zw@mail.gmail.com>
On Mon, Aug 11, 2025 at 9:01 AM Nick Cleaton <[email protected]> wrote:
> If I take an instantaneous filesystem-level snapshot of the postgres
> data directory underneath a running postgres server, is that a safe
> backup without doing any pg_start_backup/pg_stop_backup ?
>
> It seems like it should be, so long as I get an atomic snapshot that
> includes both data and wal, because starting up from that snapshot
> should look the same as recovering from an unclean postgres shutdown
> due to a kernel panic.
>
We once restored a whole-system VMware snapshot to a new VM (new IP address
and everything). When I logged in, PG started up without a hiccup; it
took a couple of minutes while WALs rolled forward, but that's to be
expected.
Postgresql didn't (and doesn't) know anything about when snapshots are
taken.
--
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!
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Subject: Re: Backups with filesystem snapshots
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