Re: Documentation for initdb option --waldir

On Wed, Mar 26, 2025 at 2:35 AM PG Doc comments form <noreply(at)postgresql(dot)org>
wrote:

> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/17/app-initdb.html
> Description:
>
> Hi all,
>
> During troubleshooting with a customer we found that it might help to know
> that initdb will create a symbolic link from data/pg_wal to the custom
> directory with the option --waldir.
>
>
Thank you for the observation. This indeed seems like something we should
cover in a bit more detail. How does the proposed patch (attached) look?

The main initdb change, added to Notes, is:

The pg_wal subdirectory will always exist within the data directory. This
is where PostgreSQL sends its write-ahead log (WAL) files. Specifying the
--waldir option turns this subdirectory entry into a symbolic link. In
general, this is only useful if the remote location is on a different
physical device. An existing directory must be empty and should not be a
mount point. The directory will be created (including missing parents) if
necessary.

David J.