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From: Nick Cleaton <nick@cleaton.net>
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Subject: Backups with filesystem snapshots
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Precedence: bulk

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.