I am in a severe pinch here.  A while back I upgraded from 4.2.8 to 4.3.3 and only had one step remaining and that was to set the cluster compat level to 4.3 (from 4.2).  When I tried this it gave the usual warning that each VM would have to be rebooted to complete, but then I got my first unusual piece when it then told me next that this could not be completed until each host was in maintenance mode.  Quirky I thought, but I stopped all VMs and put both hosts into maintenance mode.  I then set the cluster to 4.3.  Things didn't want to become active again and I eventually noticed that I was being told the DC needed to be 4.3 as well.  Don't remember that from before, but oh well that was easy. However, the DC and SD remains down.  The hosts are non-op.  I've powered everything off and started fresh but still wind up in the same state.  Hosts will look like their active for a bit (green triangle) but then go non-op after about a minute.  It appears that my iSCSI sessions are active/logged in.  The one glaring thing I see in the logs is this in vdsm.log: 2019-04-05 12:03:30,225-0400 ERROR (monitor/07bb1bf) [storage.Monitor] Setting up monitor for 07bb1bf8-3b3e-4dc0-bc43-375b09e06683 failed (monitor:329) Traceback (most recent call last):   File "/usr/lib/python2.7/site-packages/vdsm/storage/monitor.py", line 326, in _setupLoop     self._setupMonitor()   File "/usr/lib/python2.7/site-packages/vdsm/storage/monitor.py", line 348, in _setupMonitor     self._produceDomain()   File "/usr/lib/python2.7/site-packages/vdsm/utils.py", line 158, in wrapper     value = meth(self, *a, **kw)   File "/usr/lib/python2.7/site-packages/vdsm/storage/monitor.py", line 366, in _produceDomain     self.domain = sdCache.produce(self.sdUUID)   File "/usr/lib/python2.7/site-packages/vdsm/storage/sdc.py", line 110, in produce     domain.getRealDomain()   File "/usr/lib/python2.7/site-packages/vdsm/storage/sdc.py", line 51, in getRealDomain     return self._cache._realProduce(self._sdUUID)   File "/usr/lib/python2.7/site-packages/vdsm/storage/sdc.py", line 134, in _realProduce     domain = self._findDomain(sdUUID)   File "/usr/lib/python2.7/site-packages/vdsm/storage/sdc.py", line 151, in _findDomain     return findMethod(sdUUID)   File "/usr/lib/python2.7/site-packages/vdsm/storage/sdc.py", line 176, in _findUnfetchedDomain     raise se.StorageDomainDoesNotExist(sdUUID) StorageDomainDoesNotExist: Storage domain does not exist: (u'07bb1bf8-3b3e-4dc0-bc43-375b09e06683',) How do I proceed to get back operational?