diff --git a/src/middlewared/middlewared/main.py b/src/middlewared/middlewared/main.py
index 1912e0e18d17..95f27ca6db8a 100644
--- a/src/middlewared/middlewared/main.py
+++ b/src/middlewared/middlewared/main.py
@@ -1262,7 +1262,7 @@ def _loop_monitor_thread(self):
             if last == current:
                 frame = sys._current_frames()[self.__thread_id]
                 stack = traceback.format_stack(frame, limit=-10)
-                self.logger.warn(''.join(['Task seems blocked:'] + stack))
+                self.logger.warn(''.join(['Task seems blocked:\n'] + stack))
             last = current
 
     def run(self):
diff --git a/src/middlewared/middlewared/plugins/update.py b/src/middlewared/middlewared/plugins/update.py
index 24498d7a4c73..0f82fe31538d 100644
--- a/src/middlewared/middlewared/plugins/update.py
+++ b/src/middlewared/middlewared/plugins/update.py
@@ -2,6 +2,7 @@
 from middlewared.schema import accepts, Bool, Dict, Str
 from middlewared.service import job, private, CallError, Service
 
+from datetime import datetime
 import enum
 import errno
 import os
@@ -72,11 +73,12 @@ def compare_trains(t1, t2):
     ):
         return CompareTrainsResult.MINOR_UPGRADE
 
-    if (
-        isinstance(v1[1], int) and isinstance(v2[1], int) and v1[1] > v2[1] or
-        not isinstance(v2[1], int) and v1[1] > 0
-    ):
-        return CompareTrainsResult.MINOR_DOWNGRADE
+    if isinstance(v1[1], int):
+        if (
+            isinstance(v2[1], int) and v1[1] > v2[1] or
+            not isinstance(v2[1], int) and v1[1] > 0
+        ):
+            return CompareTrainsResult.MINOR_DOWNGRADE
 
 
 class CheckUpdateHandler(object):
@@ -456,6 +458,15 @@ async def update(self, job, attrs=None):
         )
         await self.middleware.call('cache.put', 'update.applied', True)
 
+        if (
+            await self.middleware.call_sync('system.is_freenas') or
+            (
+                await self.middleware.call('failover.licensed') and
+                await self.middleware.call('failover.status') != 'BACKUP'
+            )
+        ):
+            await self.middleware.call('update.take_systemdataset_samba4_snapshot')
+
         if attrs.get('reboot'):
             await self.middleware.call('system.reboot', {'delay': 10})
         return True
@@ -645,3 +656,27 @@ def destroy_upload_location(self):
         )
         if cp.returncode != 0:
             raise CallError(f'Could not destroy memory device: {cp.stderr}')
+
+    @private
+    def take_systemdataset_samba4_snapshot(self):
+        basename = self.middleware.call_sync('systemdataset.config')['basename']
+        if basename is None:
+            self.logger.warning('System dataset is not available, not taking snapshot')
+            return
+
+        dataset = f'{basename}/samba4'
+
+        proc = subprocess.run(['zfs', 'list', '-t', 'snapshot', '-H', '-o', 'name', '-s', 'name', '-d', '1', dataset],
+                              stdout=subprocess.PIPE, stderr=subprocess.PIPE, encoding='utf8', errors='ignore')
+        if proc.returncode != 0:
+            self.logger.warning('Unable to list dataset %s snapshots: %s', dataset, proc.stderr)
+            return
+
+        snapshots = [s.split('@')[1] for s in proc.stdout.strip().split()]
+        for snapshot in [s for s in snapshots if s.startswith('update--')][:-4]:
+            self.logger.info('Deleting dataset %s snapshot %s', dataset, snapshot)
+            subprocess.run(['zfs', 'destroy', f'{dataset}@{snapshot}'])
+
+        current_version = "-".join(self.middleware.call_sync("system.info")["version"].split("-")[1:])
+        snapshot = f'update--{datetime.utcnow().strftime("%Y-%m-%d-%H-%M")}--{current_version}'
+        subprocess.run(['zfs', 'snapshot', f'{dataset}@{snapshot}'])
diff --git a/src/middlewared/middlewared/pytest/unit/plugins/test_update.py b/src/middlewared/middlewared/pytest/unit/plugins/test_update.py
index 161ed5e7ccd6..95c7b3635dc0 100644
--- a/src/middlewared/middlewared/pytest/unit/plugins/test_update.py
+++ b/src/middlewared/middlewared/pytest/unit/plugins/test_update.py
@@ -20,6 +20,7 @@
     ("FreeNAS-11.2-STABLE", "FreeNAS-11-STABLE", CompareTrainsResult.MINOR_DOWNGRADE),
 
     ("FreeNAS-9.10-STABLE", "FreeNAS-9.10-STABLE", None),
+    ("FreeNAS-11-Nightlies", "FreeNAS-11-Nightlies", None),
 ])
 def test__compare_trains(t1, t2, result):
     assert compare_trains(t1, t2) == result