zfs sharenfs to multiple subnets - found a dirty looking hack

[Bernd Walter]

On Mon, Dec 28, 2009 at 11:52:28PM +0100, Marco van Tol wrote:
> Hi there,
> 
> I would like to refer to a thread in this list about zfs exporting to
> multiple subnets using sharenfs.  The thread I mean is this one:
> http://lists.freebsd.org/pipermail/freebsd-fs/2008-September/005158.html
> I wasn't subscribed at the time, so I'm just referencing to the thread.
> 
> I was testing and needed to also export a filesystem to multiple subnets,
> and found something out that may or may not be allowed.
> 
> What happens is you start to type
> zfs set sharenfs="<arguments>
> and don't close the double quote.  The result on the following lines will
> literally make it to /etc/zfs/exports, and make it work as desired.
> 
> A full session would look like: 
> (Bear with me for typo's, I didn't copy-paste)
> 
> zfs set sharenfs="-maproot=root -network 10.0.0.0/24
> > /path/to/mountpoint	-maproot=root -network 192.168.0.0/24
> > /path/to/mountpoint	-maproot=root -network 172.16.0.0/24"	pool0/space
> 
> This translates to an /etc/zfs/exports like:
> ----< cut here >----
> /path/to/mountpoint	-maproot=root -network=10.0.0.0/24
> /path/to/mountpoint	-maproot=root -network=192.168.0.0/24
> /path/to/mountpoint	-maproot=root -network=172.16.0.0/24
> ----< cut here >----
> 
> The resulting "zfs get sharenfs" looks like:
> ----< cut here >----
> pool0/space	sharenfs	-maproot=root -network=10.0.0.0/24
> /path/to/mountpoint	-maproot=root -network=192.168.0.0/24
> /path/to/mountpoint	-maproot=root -network=172.16.0.0/24	local
> ----< cut here >----
> 
> This all makes it work so that it exports the pool to multiple subnets,
> possibly with their own properties.
> 
> Question is however, how desirable is it that this works? ;-)

The really cool thing about using zfs property instead of manual
exports line is the ability to inherit export options, but since
you need to write the path into the argument...
It would be nice however if the export-file creator would parse the
newline and automatically prepend the path to each line.

-- 
B.Walter <bernd at bwct.de> http://www.bwct.de
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.