Re: union mounts, mfs, and newsyslog

[David Holland <dholland-current%netbsd.org@localhost>]

On Thu, Jul 09, 2009 at 06:36:34AM -0400, Martin S. Weber wrote:
 > > > > > this way you can use tmpfs over union. this is the only way to get
 > > > > > tmpfs over union working. i'm using this since a while. it isn't
 > > > > > documented anywhere.
 > > > > 
 > > > > Sounds like a good addition to the tmpfs man page.  :)
 > > > 
 > > > And an answer to kern/35112 ?
 > > 
 > > No, because union mount != unionfs.
 > 
 > At the time of the PR there was no unionfs. The unionfs I talk
 > about in the PR is mount_union, not mount_unionfs. Back then it
 > didn't make no difference whether you talked about msdosfs or msdos
 > or unionfs or union...

Uh... mount_union and mount_unionfs are broadly the same, and their
common ancestor dates back to 4.4. (As noted elsewhere, sys/fs/unionfs
is a partially-completed port of FreeBSD's descendent version of the
4.4 unionfs, while sys/fs/union is our own.)

"union mount" = mount -o union
"unionfs" = mount -t union

which are quite different things.

Confusion on this subject is routine, which is why we desperately need
doc fixes.

-- 
David A. Holland
dholland%netbsd.org@localhost