Change request for mount_null manpage

[Tony Maher]

Hello Andrew,

<this is a followup to list as suggested in private email>

> Andrew J Caines wrote:

>> I'm using mount_null now for some months - and i never had a problem
>> with this.

> Are you using it for rw mounts and if so, then what kind or write volume
> and sizes do you handle?
>
> Usually when this comes up, folks are using null ro mounts and the rare
> (and sometime unintentional) rw mounts do little or no writing. If anyone
> is doing significant volume or size writes, then I've not heared mention
> of it.

I also have been using nullfs (since Jun 30 2001) on a number of systems
(from 4.3-> 4.8) including my main workstation and multiuser servers.
The mounts are rw.

FreeBSD dt.home 4.8-STABLE FreeBSD 4.8-STABLE #2: Wed Apr 16 13:00:01 EST 2003

/space/home/staff           4817509 2995755 1436354    68%  /home/staff
/space/db/mysql             4817509 2995755 1436354    68%  /db/mysql
/space/db/pgsql             4817509 2995755 1436354    68%  /db/pgsql
/space/usr/cvs              4817509 2995755 1436354    68%  /usr/cvs
/space/usr/doc              4817509 2995755 1436354    68%  /usr/doc
/space/usr/ports            4817509 2995755 1436354    68%  /usr/ports
/space/usr/src              4817509 2995755 1436354    68%  /usr/src
/var/obj                    1016303  747549  187450    80%  /usr/obj
/space/usr/local/office52   4817509 2995755 1436354    68%  /usr/local/office52

I have built world many times and compiled ports without problem.

I have an outstanding PR regarding nullfs
http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/28566

I have now removed /usr/hack nullfs mount and retested startx.
It all works fine now and I think this PR can now be closed (I'll submit
PR followup after some more testing).  Also at the time of this PR I stopped
using nullfs mounts for /home because linux binaries would not work (no PR 
for this).  I have also retested this and everything works fine.

I think the warning in mount_null man page could be toned down.

As noted in the '5.1-RELEASE TODO' emails nullfs is somewhat broken
in -current.

cheers
--
tonym