Subject: Re: mount_union
To: None <current-users@NetBSD.ORG>
From: der Mouse <mouse@Collatz.McRCIM.McGill.EDU>
List: current-users
Date: 03/05/1996 06:50:41
> I just built myself a kernel with options UNION, but even so, when I
> do a

> mount -t union /usr/src/sys /home/sys

> I see:

> union: operation not supported.

> What's wrong?

Almost certainly, the top layer is a filesystem that doesn't support
whiteouts.  When this is the case, the union mount has to be read-only.
Yes, this is a flaw (I would almost say "bug") in the union filesystem.

What supports whiteouts?  Under NetBSD, 4.4-style FFS is the only one,
I believe.

					der Mouse