Re: could not open file "global/pg_filenode.map": Operation not permitted

On Fri, 22 Mar 2024 at 15:01, Nick Renders <postgres(at)arcict(dot)com> wrote:

>
> We now have a second machine with this issue: it is an Intel Mac mini
> running macOS Sonoma (14.4) and PostgreSQL 16.2.
> This one only has a single Data directory, so there are no multiple
> instances running.
>

I don't think that having a single Data directory prevents multiple
instances from running. That's more of a matter of how often pg_ctl was
called with the start command for that particular data directory.

> I installed Postgres yesterday and restored a copy from our live database
> in the Data directory.

How did you restore that copy? Was that a file-based copy perhaps? Your
files may have incorrect owners or permissions in that case.

> The Postgres process started up without problems, but after 40 minutes it
> started throwing the same errors in the log:
>
> 2024-03-21 11:49:27.410 CET [1655] FATAL: could not open file
> "global/pg_filenode.map": Operation not permitted
> 2024-03-21 11:49:46.955 CET [1760] FATAL: could not open file
> "global/pg_filenode.map": Operation not permitted
> 2024-03-21 11:50:07.398 CET [965] LOG: could not open file
> "postmaster.pid": Operation not permitted; continuing anyway
>

It's possible that some other process put a lock on these files. Spotlight
perhaps? Or TimeMachine?

> I stopped and started the process, and it continued working again until
> around 21:20, when the issue popped up again. I wasn't doing anything on
> the machine at that time, so I have no idea what might have triggered it.
>
> Is there perhaps some feature that I can enable that logs which processes
> use these 2 files?
>

IIRC, MacOS comes shipped with the lsof command, which will tell you which
processes have a given file open. See man lsof.

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