ZFS and Jail :: nullfs mount :: nothing visible from host

[SK]

On 08/12/2016 17:02, Alexander Leidinger wrote:
> Quoting SK <fbstable at cps-intl.org> (from Thu, 8 Dec 2016 16:41:29 +0000):
>
>> Thank you for your response. I tried setting it up like that (use zfs 
>> set jailed=on), and that did not work. I could not even run zfs from 
>> within the jail. Maybe I did something wrong -- so I am setting up a 
>> test box where I can try them all out.
>
> You need to have the zfs device visible in the jail, for this you need 
> to use a devfs rule at jail-start which makes it visible in the jail.
>
> See http://www.leidinger.net/blog/2011/05/19/how-i-setup-a-jail-host 
> in the part "Ad­di­tional devfs rules for Jails" 
> (devfsrules_jail_withzfs).
>
> Bye,
> Alexander.
Dear Miroslav, Alexander

Thank you both for the pointers. As soon as the test machine finishes 
compiling the world (I am using vimage, need custom kernel), I will give 
that a try.

However, I did set up the things Miroslav suggested, along with tweaking 
the sysctl variables for jail zfs mount, and also setting the zfs 
jailed=on -- but on the existing system that had no effect whatsoever 
(even after a restart). So, I am thinking this might be due to the fact 
that all jails are nullfs mounted, hence the test box.

I will update once I get the chance to play with the information you two 
kindly provided and let you know how it goes.

Thanks and regards
SK