Re: Bypassing Directory Ownership Check in PostgreSQL 16.6 with Secure z/OS NFS (AT-TLS)

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Amol Inamdar <amol.aai@gmail.com>
Cc: Laurenz Albe <laurenz.albe@cybertec.at>, pgsql-general@lists.postgresql.org
Date: 2025-07-17T05:14:33Z
Lists: pgsql-general
Amol Inamdar <amol.aai@gmail.com> writes:
> @Laurenz Albe <laurenz.albe@cybertec.at>
>> If you pre-create the data directory with the appropriate permissions,
>> what keeps you from giving ownership to the correct user too?

> Our NFS server is not a regular linux based server,
> it's on zOS (Mainframes) with AT-TLS security enabled,
> hence it doesn't allow changing of ownership.

Not only is that not a fit storage substrate for Postgres,
it's pretty hard to imagine that it's a fit substrate for
anything.  "Every file on this filesystem must belong to the
same owner" is a concept that should have gone out with
floppy disks.

You need some extremely fundamental re-examination of your
design decisions.  At the moment I am content to say that
Postgres does not support this storage mechanism and we
do not intend to do so in the future.

			regards, tom lane