From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tom Korach <tom@safekeep.com>
cc: pgsql-admin@lists.postgresql.org
Subject: Re: Is file system replication sufficient to recovery?
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Comments: In-reply-to Tom Korach <tom@safekeep.com>
	message dated "Thu, 30 Dec 2021 12:04:58 -0500"
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Date: Thu, 30 Dec 2021 12:20:45 -0500
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Tom Korach <tom@safekeep.com> writes:
> We have a Postgresql instance (0.5-4TB in size) used for development and
> on-line reporting.
> We do not need high-availability, but we do need:
> 1. Quick disaster recovery (<1 hour) is important.
> 2. Recovery from corruption of the server or mistakes.

> Will file-system replication be enough to achieve this goal?

What do you mean exactly by "file-system replication"?  Something
equivalent to rsync will absolutely not work against a running
Postgres server, because it won't capture a consistent state of
all the files.  If you have (and trust) a filesystem with snapshot
capabilities, it might work to take a filesystem snapshot and hold
onto it long enough to rsync from the snapshot.  I'm not sure about
the reliability or performance implications of such a setup, though.
See

https://www.postgresql.org/docs/current/backup-file.html

> Do we also need WAL file archiving?

Not as long as you capture the currently-active WAL files along
with the database contents.

			regards, tom lane