Cannot remove SLOGS from Encrypted Pool

[Constantin]

I am in the process of bringing up my SuperMicro board. Here is a curious error I ran into with my encrypted pool - it's not possible to remove a SLOG! In my case, I want to replace the mirrored SLOGs with a single Optane module. Not possible. It is possible to take them offline, but they cannot be removed.

Is the only remedy to nuke and rebuild the pool?

Code:

Error: Traceback (most recent call last):

  File "/usr/local/lib/python3.6/site-packages/tastypie/resources.py", line 219, in wrapper
    response = callback(request, *args, **kwargs)

  File "./freenasUI/api/resources.py", line 916, in remove_disk
    notifier().zfs_remove_disk(obj, deserialized.get('label'))

  File "./freenasUI/middleware/notifier.py", line 1114, in zfs_remove_disk
    raise MiddlewareError('Disk could not be removed: "%s"' % error)

freenasUI.middleware.exceptions.MiddlewareError: [MiddlewareError: Disk could not be removed: "cannot remove /dev/gptid/58131117-01b8-11e9-a45f-00074334a5b0.eli: operation not supported on this type of pool, "]

 

[Constantin]

Code:

Error: Traceback (most recent call last):

  File "/usr/local/lib/python3.6/site-packages/tastypie/resources.py", line 219, in wrapper
    response = callback(request, *args, **kwargs)

  File "./freenasUI/api/resources.py", line 890, in online_disk
    notifier().zfs_online_disk(obj, deserialized.get('label'))

  File "./freenasUI/middleware/notifier.py", line 1064, in zfs_online_disk
    assert volume.vol_encrypt == 0

AssertionError

I was able to take them offline, resulting in a degraded pool, if I try to online them, I get the above.

Why is the pool considered degraded when a SLOG is taken offline?

 

[Constantin]

Created a case on redmine. Interesting... the Optane SLOG can be connected and disconnected w/o issues (i.e. remove) which allowed me to benchmark it. The old SLOGs, not so much. Curious!

 

[seanm]

Link to ticket?

 

[Constantin]

Sure thing, look here.