2007/416 NFSv4 Mirror-mounts

[Tom Haynes]

Nicolas Williams wrote:
> On Tue, Jul 17, 2007 at 10:29:06PM +0100, Calum Mackay wrote:
>   
>> Interaction with the automounter
>>
>> Where there is an existing automount trigger point setup for a
>> particular server filesystem, it will take precedence over
>> mirror-mounting, i.e. a mirror-mount will not occur for that filesystem.
>>     
>
> So, no mirror mounts in /net?!  Please say it ain't so :(
>
> The current /net -hosts automount map depends on the MOUNT protocol to
> get hierarchical mount information and does honor hierarchical mounts,
> but it does not refresh this ever, which is a big problem when the
> server uses ZFS (and therefore likes to make/destroy datasets willy
> nilly).  Mirror mounts would clearly solve this problem.
>
> Nico
>   


It ain't so.

I think the intent here is that if you have a choice over an automount 
or a mirror mount, we take the
automount.

But if there is no automount entry and there is a chance to mirror 
mount, then we will of course
mirror mount.

Assume that a server has a zfs pool called tank and it is serving up 
home dirs.

So:

cd /net/server

No mirror mounts have occurred.

No:

cd tank

Okay, this will cause a mirror mount to occur. And as we dive down 
farther, more will occur.