Jail/Plugin pool not able to be selected

[Tabmowtez]

I've finished the setup for the most part of my new TrueNAS machine and have started on my jails/plugins.
When I initially click on either Jails or Plugins it asks me for a pool to use as it's storage (I only have the 1 pool).
This is the error I get:

[EFAULT] Failed to activate data: ZFS pool "data" root dataset is locked

I've been through the root dataset options but I have no idea what 'locked' means in this context.
Child datasets and zvol's have created fine and are working as per normal.
Anyone encountered this issue before?

The full stacktrace is below:

Code:

Error: Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/middlewared/plugins/jail_freebsd.py", line 1442, in activate
    iocage.activate(pool['name'])
  File "/usr/local/lib/python3.8/site-packages/iocage_lib/iocage.py", line 368, in activate
    ioc_common.logit(
  File "/usr/local/lib/python3.8/site-packages/iocage_lib/ioc_common.py", line 107, in logit
    callback(content, exception)
  File "/usr/local/lib/python3.8/site-packages/iocage_lib/ioc_common.py", line 80, in callback
    raise callback_exception(message)
RuntimeError: ZFS pool "data" root dataset is locked

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 137, in call_method
    result = await self.middleware._call(message['method'], serviceobj, methodobj, params, app=self,
  File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1206, in _call
    return await self.run_in_executor(prepared_call.executor, methodobj, *prepared_call.args)
  File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1110, in run_in_executor
    return await loop.run_in_executor(pool, functools.partial(method, *args, **kwargs))
  File "/usr/local/lib/python3.8/concurrent/futures/thread.py", line 57, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/local/lib/python3.8/site-packages/middlewared/schema.py", line 977, in nf
    return f(*args, **kwargs)
  File "/usr/local/lib/python3.8/site-packages/middlewared/plugins/jail_freebsd.py", line 1444, in activate
    raise CallError(f'Failed to activate {pool["name"]}: {e}')
middlewared.service_exception.CallError: [EFAULT] Failed to activate data: ZFS pool "data" root dataset is locked

 

[Tabmowtez]

Ok, after doing some digging around in the iocage docs and what it does to activate, as well as comparing with my existing system, I was able to resolve the problem by mounting my root dataset.

Code:

zfs mount data

Then I went back to the jails screen and it let me choose my 'data' pool.
I'm not sure if this is a bug or not, I don't remember having to do this on previous versions of FreeNAS.
This was a fresh install of 12.0-U1.