Created attachment 588016 [details] engine.log Volumes -> select volume -> Volume Options -> nfs.disable -> Reset -> nfs.disable key is removed -> try to add nfs.disable key again -> nfs.disable key doesn't appear in the keys list.
Created attachment 588018 [details] vdsm.log
Though it sounds a little different, it is happening because of exactly same reason as 826465. Hence closing it marking as duplicate. *** This bug has been marked as a duplicate of bug 826465 ***