diff --git a/config.yaml b/config.yaml
index 8156bf1c..39688be6 100644
--- a/config.yaml
+++ b/config.yaml
@@ -211,3 +211,12 @@ options:
       .
       This needs to be set to 1 when deploying a cloud with the nova-lxd
       hypervisor.
+  no-bootstrap:
+    type: boolean
+    default: False
+    description: |
+      Causes the charm to not do any of the initial bootstrapping of the
+      Ceph monitor cluster. This is only intended to be used when migrating
+      from the ceph all-in-one charm to a ceph-mon / ceph-osd deployment.
+      Refer to the Charm Deployment guide at https://docs.openstack.org/charm-deployment-guide/latest/
+      for more information.
diff --git a/hooks/bootstrap-source-relation-changed b/hooks/bootstrap-source-relation-changed
new file mode 120000
index 00000000..52d96630
--- /dev/null
+++ b/hooks/bootstrap-source-relation-changed
@@ -0,0 +1 @@
+ceph_hooks.py
\ No newline at end of file
diff --git a/hooks/bootstrap-source-relation-departed b/hooks/bootstrap-source-relation-departed
new file mode 120000
index 00000000..52d96630
--- /dev/null
+++ b/hooks/bootstrap-source-relation-departed
@@ -0,0 +1 @@
+ceph_hooks.py
\ No newline at end of file
diff --git a/hooks/ceph_hooks.py b/hooks/ceph_hooks.py
index 42a9a21b..9de2cd75 100755
--- a/hooks/ceph_hooks.py
+++ b/hooks/ceph_hooks.py
@@ -178,6 +178,9 @@ JOURNAL_ZAPPED = '/var/lib/ceph/journal_zapped'
 @hooks.hook('config-changed')
 @harden()
 def config_changed():
+    # Get the cfg object so we can see if the no-bootstrap value has changed
+    # and triggered this hook invocation
+    cfg = config()
     if config('prefer-ipv6'):
         assert_charm_supports_ipv6()
 
@@ -192,24 +195,32 @@ def config_changed():
         update_nrpe_config()
 
     if is_leader():
-        if not leader_get('fsid') or not leader_get('monitor-secret'):
-            if config('fsid'):
-                fsid = config('fsid')
-            else:
-                fsid = "{}".format(uuid.uuid1())
-            if config('monitor-secret'):
-                mon_secret = config('monitor-secret')
-            else:
-                mon_secret = "{}".format(ceph.generate_monitor_secret())
-            status_set('maintenance', 'Creating FSID and Monitor Secret')
-            opts = {
-                'fsid': fsid,
-                'monitor-secret': mon_secret,
-            }
-            log("Settings for the cluster are: {}".format(opts))
-            leader_set(opts)
-    else:
-        if leader_get('fsid') is None or leader_get('monitor-secret') is None:
+        if not config('no-bootstrap'):
+            if not leader_get('fsid') or not leader_get('monitor-secret'):
+                if config('fsid'):
+                    fsid = config('fsid')
+                else:
+                    fsid = "{}".format(uuid.uuid1())
+                if config('monitor-secret'):
+                    mon_secret = config('monitor-secret')
+                else:
+                    mon_secret = "{}".format(ceph.generate_monitor_secret())
+                status_set('maintenance', 'Creating FSID and Monitor Secret')
+                opts = {
+                    'fsid': fsid,
+                    'monitor-secret': mon_secret,
+                }
+                log("Settings for the cluster are: {}".format(opts))
+                leader_set(opts)
+        elif cfg.changed('no-bootstrap') and \
+                is_relation_made('bootstrap-source'):
+            # User changed the no-bootstrap config option, we're the leader,
+            # and the bootstrap-source relation has been made. The charm should
+            # be in a blocked state indicating that the no-bootstrap option
+            # must be set. This block is invoked when the user is trying to
+            # get out of that scenario by enabling no-bootstrap.
+            bootstrap_source_relation_changed()
+    elif leader_get('fsid') is None or leader_get('monitor-secret') is None:
             log('still waiting for leader to setup keys')
             status_set('waiting', 'Waiting for leader to setup keys')
             sys.exit(0)
@@ -232,7 +243,11 @@ def get_mon_hosts():
     addr = get_public_addr()
     hosts.append('{}:6789'.format(format_ipv6_addr(addr) or addr))
 
-    for relid in relation_ids('mon'):
+    rel_ids = relation_ids('mon')
+    if config('no-bootstrap'):
+        rel_ids += relation_ids('bootstrap-source')
+
+    for relid in rel_ids:
         for unit in related_units(relid):
             addr = relation_get('ceph-public-address', unit, relid)
             if addr is not None:
@@ -265,8 +280,70 @@ def mon_relation_joined():
                      relation_settings={'ceph-public-address': public_addr})
 
 
+@hooks.hook('bootstrap-source-relation-changed')
+def bootstrap_source_relation_changed():
+    """Handles relation data changes on the bootstrap-source relation.
+
+    The bootstrap-source relation to share remote bootstrap information with
+    the ceph-mon charm. This relation is used to exchange the remote
+    ceph-public-addresses which are used for the mon's, the fsid, and the
+    monitor-secret.
+    """
+    if not config('no-bootstrap'):
+        status_set('blocked', 'Cannot join the bootstrap-source relation when '
+                              'no-bootstrap is False')
+        return
+
+    if not is_leader():
+        log('Deferring leader-setting updates to the leader unit')
+        return
+
+    curr_fsid = leader_get('fsid')
+    curr_secret = leader_get('monitor-secret')
+    for relid in relation_ids('bootstrap-source'):
+        for unit in related_units(relid=relid):
+            mon_secret = relation_get('monitor-secret', unit, relid)
+            fsid = relation_get('fsid', unit, relid)
+
+            if not (mon_secret and fsid):
+                log('Relation data is not ready as the fsid or the '
+                    'monitor-secret are missing from the relation: '
+                    'mon_secret = %s and fsid = %s ' % (mon_secret, fsid))
+                continue
+
+            if not (curr_fsid or curr_secret):
+                curr_fsid = fsid
+                curr_secret = mon_secret
+            else:
+                # The fsids and secrets need to match or the local monitors
+                # will fail to join the mon cluster. If they don't,
+                # bail because something needs to be investigated.
+                assert curr_fsid == fsid, \
+                    "bootstrap fsid '%s' != current fsid '%s'" % (
+                        fsid, curr_fsid)
+                assert curr_secret == mon_secret, \
+                    "bootstrap secret '%s' != current secret '%s'" % (
+                        mon_secret, curr_secret)
+
+            opts = {
+                'fsid': fsid,
+                'monitor-secret': mon_secret,
+            }
+
+            log('Updating leader settings for fsid and monitor-secret '
+                'from remote relation data: %s' % opts)
+            leader_set(opts)
+
+    # The leader unit needs to bootstrap itself as it won't receive the
+    # leader-settings-changed hook elsewhere.
+    if curr_fsid:
+        mon_relation()
+
+
 @hooks.hook('mon-relation-departed',
-            'mon-relation-changed')
+            'mon-relation-changed',
+            'leader-settings-changed',
+            'bootstrap-source-relation-departed')
 def mon_relation():
     if leader_get('monitor-secret') is None:
         log('still waiting for leader to setup keys')
@@ -320,7 +397,8 @@ def mon_relation():
 
 def notify_osds():
     for relid in relation_ids('osd'):
-        osd_relation(relid)
+        for unit in related_units(relid):
+            osd_relation(relid=relid, unit=unit)
 
 
 def notify_radosgws():
@@ -341,7 +419,7 @@ def notify_client():
 
 @hooks.hook('osd-relation-joined')
 @hooks.hook('osd-relation-changed')
-def osd_relation(relid=None):
+def osd_relation(relid=None, unit=None):
     if ceph.is_quorum():
         log('mon cluster in quorum - providing fsid & keys')
         public_addr = get_public_addr()
@@ -354,7 +432,7 @@ def osd_relation(relid=None):
                                                   caps=ceph.osd_upgrade_caps),
         }
 
-        unit = remote_unit()
+        unit = unit or remote_unit()
         settings = relation_get(rid=relid, unit=unit)
         """Process broker request(s)."""
         if 'broker_req' in settings:
@@ -590,6 +668,14 @@ VERSION_PACKAGE = 'ceph-common'
 def assess_status():
     '''Assess status of current unit'''
     application_version_set(get_upstream_version(VERSION_PACKAGE))
+
+    # Check that the no-bootstrap config option is set in conjunction with
+    # having the bootstrap-source relation established
+    if not config('no-bootstrap') and is_relation_made('bootstrap-source'):
+        status_set('blocked', 'Cannot join the bootstrap-source relation when '
+                              'no-bootstrap is False')
+        return
+
     moncount = int(config('monitor-count'))
     units = get_peer_units()
     # not enough peers and mon_count > 1
diff --git a/hooks/leader-settings-changed b/hooks/leader-settings-changed
new file mode 120000
index 00000000..52d96630
--- /dev/null
+++ b/hooks/leader-settings-changed
@@ -0,0 +1 @@
+ceph_hooks.py
\ No newline at end of file
diff --git a/metadata.yaml b/metadata.yaml
index 82f9d191..bf379593 100644
--- a/metadata.yaml
+++ b/metadata.yaml
@@ -36,3 +36,6 @@ provides:
   nrpe-external-master:
     interface: nrpe-external-master
     scope: container
+requires:
+  bootstrap-source:
+    interface: ceph-bootstrap
diff --git a/unit_tests/test_ceph_hooks.py b/unit_tests/test_ceph_hooks.py
index 44288f94..ef7a0786 100644
--- a/unit_tests/test_ceph_hooks.py
+++ b/unit_tests/test_ceph_hooks.py
@@ -11,8 +11,28 @@ sys.modules['apt'] = mock_apt
 mock_apt.apt_pkg = MagicMock()
 
 import charmhelpers.contrib.storage.linux.ceph as ceph
-import ceph_hooks
+import test_utils
 
+with patch('charmhelpers.contrib.hardening.harden.harden') as mock_dec:
+    mock_dec.side_effect = (lambda *dargs, **dkwargs: lambda f:
+                            lambda *args, **kwargs: f(*args, **kwargs))
+    import ceph_hooks
+
+
+TO_PATCH = [
+    'config',
+    'is_leader',
+    'is_relation_made',
+    'leader_get',
+    'leader_set',
+    'log',
+    'mon_relation',
+    'relation_ids',
+    'related_units',
+    'relation_get',
+    'relations_of_type',
+    'status_set',
+]
 
 CHARM_CONFIG = {'config-flags': '',
                 'auth-supported': False,
@@ -193,7 +213,7 @@ class RelatedUnitsTestCase(unittest.TestCase):
 
     @patch.object(ceph_hooks, 'relation_ids')
     @patch.object(ceph_hooks, 'related_units')
-    def test_related_ods_single_relation(self,
+    def test_related_osd_single_relation(self,
                                          related_units,
                                          relation_ids):
         relation_ids.return_value = ['osd:0']
@@ -205,7 +225,7 @@ class RelatedUnitsTestCase(unittest.TestCase):
 
     @patch.object(ceph_hooks, 'relation_ids')
     @patch.object(ceph_hooks, 'related_units')
-    def test_related_ods_multi_relation(self,
+    def test_related_osd_multi_relation(self,
                                         related_units,
                                         relation_ids):
         relation_ids.return_value = ['osd:0', 'osd:23']
@@ -218,3 +238,119 @@ class RelatedUnitsTestCase(unittest.TestCase):
             call('osd:0'),
             call('osd:23')
         ])
+
+
+class BootstrapSourceTestCase(test_utils.CharmTestCase):
+
+    def setUp(self):
+        super(BootstrapSourceTestCase, self).setUp(ceph_hooks, TO_PATCH)
+        self.config.side_effect = self.test_config.get
+        self.leader_get.side_effect = self.test_leader_settings.get
+        self.leader_set.side_effect = self.test_leader_settings.set
+        self.relation_get.side_effect = self.test_relation.get
+        self.test_config.set('no-bootstrap', True)
+        self.is_leader.return_value = True
+        self.relation_ids.return_value = ['bootstrap-source:0']
+        self.related_units.return_value = ['ceph/0', 'ceph/1', 'ceph/2']
+
+    def test_bootstrap_source_no_bootstrap(self):
+        """Ensure the config option of no-bootstrap is set to continue"""
+        self.test_config.set('no-bootstrap', False)
+        ceph_hooks.bootstrap_source_relation_changed()
+        self.status_set.assert_called_once_with('blocked',
+                                                'Cannot join the '
+                                                'bootstrap-source relation '
+                                                'when no-bootstrap is False')
+
+    def test_bootstrap_source_not_leader(self):
+        """Ensure the processing is deferred to the leader"""
+        self.is_leader.return_value = False
+        ceph_hooks.bootstrap_source_relation_changed()
+        self.assertEqual(self.leader_set.call_count, 0)
+
+    def test_bootstrap_source_relation_data_not_ready(self):
+        """Ensures no bootstrapping done if relation data not present"""
+        ceph_hooks.bootstrap_source_relation_changed()
+        expected_calls = []
+        relid = 'bootstrap-source:0'
+        for unit in ('ceph/0', 'ceph/1', 'ceph/2'):
+            expected_calls.append(call('monitor-secret', unit, relid))
+            expected_calls.append(call('fsid', unit, relid))
+        self.relation_get.has_calls(expected_calls)
+        self.assertEqual(self.leader_set.call_count, 0)
+        self.assertEqual(self.mon_relation.call_count, 0)
+
+    def test_bootstrap_source_good_path(self):
+        """Tests the good path where all is setup and relations established"""
+        self.test_relation.set({'monitor-secret': 'abcd',
+                                'fsid': '1234'})
+        ceph_hooks.bootstrap_source_relation_changed()
+        self.leader_set.assert_called_with({'fsid': '1234',
+                                            'monitor-secret': 'abcd'})
+        self.mon_relation.assert_called_once_with()
+
+    def test_bootstrap_source_different_fsid_secret(self):
+        """Tests where the bootstrap relation has a different fsid"""
+        self.test_relation.set({'monitor-secret': 'abcd',
+                                'fsid': '1234'})
+        self.test_leader_settings.set({'monitor-secret': 'mysecret',
+                                       'fsid': '7890'})
+        self.assertRaises(AssertionError,
+                          ceph_hooks.bootstrap_source_relation_changed)
+
+    @patch.object(ceph_hooks, 'emit_cephconf')
+    @patch.object(ceph_hooks, 'create_sysctl')
+    @patch.object(ceph_hooks, 'check_for_upgrade')
+    @patch.object(ceph_hooks, 'get_mon_hosts')
+    @patch.object(ceph_hooks, 'bootstrap_source_relation_changed')
+    def test_config_changed_no_bootstrap_changed(self,
+                                                 bootstrap_source_rel_changed,
+                                                 get_mon_hosts,
+                                                 check_for_upgrade,
+                                                 create_sysctl,
+                                                 emit_ceph_conf):
+        """Tests that changing no-bootstrap invokes the bs relation changed"""
+        self.relations_of_type.return_value = []
+        self.is_relation_made.return_value = True
+        self.test_config.set_changed('no-bootstrap', True)
+        ceph_hooks.config_changed()
+        bootstrap_source_rel_changed.assert_called_once()
+
+    @patch.object(ceph_hooks, 'get_public_addr')
+    def test_get_mon_hosts(self, get_public_addr):
+        """Tests that bootstrap-source relations are used"""
+        unit_addrs = {
+            'mon:0': {
+                'ceph-mon/0': '172.16.0.2',
+                'ceph-mon/1': '172.16.0.3',
+            },
+            'bootstrap-source:1': {
+                'ceph/0': '172.16.10.2',
+                'ceph/1': '172.16.10.3',
+                'cehp/2': '172.16.10.4',
+            }
+        }
+
+        def rel_ids_side_effect(relname):
+            for key in unit_addrs.keys():
+                if key.split(':')[0] == relname:
+                    return [key]
+            return None
+
+        def rel_get_side_effect(attr, unit, relid):
+            return unit_addrs[relid][unit]
+
+        def rel_units_side_effect(relid):
+            if relid in unit_addrs:
+                return unit_addrs[relid].keys()
+            return []
+
+        self.relation_ids.side_effect = rel_ids_side_effect
+        self.related_units.side_effect = rel_units_side_effect
+        get_public_addr.return_value = '172.16.0.4'
+        self.relation_get.side_effect = rel_get_side_effect
+        hosts = ceph_hooks.get_mon_hosts()
+        self.assertEqual(hosts, [
+            '172.16.0.2:6789', '172.16.0.3:6789', '172.16.0.4:6789',
+            '172.16.10.2:6789', '172.16.10.3:6789', '172.16.10.4:6789',
+        ])
diff --git a/unit_tests/test_status.py b/unit_tests/test_status.py
index 4dfd75fa..33f924f5 100644
--- a/unit_tests/test_status.py
+++ b/unit_tests/test_status.py
@@ -32,6 +32,7 @@ TO_PATCH = [
     'status_set',
     'config',
     'ceph',
+    'is_relation_made',
     'relation_ids',
     'relation_get',
     'related_units',
@@ -64,6 +65,7 @@ class ServiceStatusTestCase(test_utils.CharmTestCase):
         self.test_config.set('monitor-count', 3)
         self.local_unit.return_value = 'ceph-mon1'
         self.get_upstream_version.return_value = '10.2.2'
+        self.is_relation_made.return_value = False
 
     @mock.patch.object(hooks, 'get_peer_units')
     def test_assess_status_no_peers(self, _peer_units):
@@ -123,3 +125,9 @@ class ServiceStatusTestCase(test_utils.CharmTestCase):
                           'ceph-mon2': True,
                           'ceph-mon3': True},
                          hooks.get_peer_units())
+
+    def test_no_bootstrap_not_set(self):
+        self.is_relation_made.return_value = True
+        hooks.assess_status()
+        self.status_set.assert_called_with('blocked', mock.ANY)
+        self.application_version_set.assert_called_with('10.2.2')
diff --git a/unit_tests/test_utils.py b/unit_tests/test_utils.py
index 97d3ee84..1665c161 100644
--- a/unit_tests/test_utils.py
+++ b/unit_tests/test_utils.py
@@ -66,6 +66,7 @@ class CharmTestCase(unittest.TestCase):
         self.obj = obj
         self.test_config = TestConfig()
         self.test_relation = TestRelation()
+        self.test_leader_settings = TestLeaderSettings()
         self.patch_all()
 
     def patch(self, method):
@@ -83,10 +84,14 @@ class TestConfig(object):
 
     def __init__(self):
         self.config = get_default_config()
+        self.config_changed = {}
+        self.config_changed.setdefault(False)
 
     def get(self, attr=None):
         if not attr:
-            return self.get_all()
+            # Return a copy of self to allow emulation closer to what
+            # hookenv.config() returns (not a dict).
+            return self
         try:
             return self.config[attr]
         except KeyError:
@@ -100,6 +105,15 @@ class TestConfig(object):
             raise KeyError
         self.config[attr] = value
 
+    def __getitem__(self, item):
+        return self.config[item]
+
+    def changed(self, attr):
+        return self.config_changed[attr]
+
+    def set_changed(self, attr, changed=True):
+        self.config_changed[attr] = changed
+
 
 class TestRelation(object):
 
@@ -117,6 +131,22 @@ class TestRelation(object):
         return None
 
 
+class TestLeaderSettings(object):
+
+    def __init__(self, settings={}):
+        self.settings = settings
+
+    def set(self, settings):
+        self.settings = settings
+
+    def get(self, attr=None):
+        if attr is None:
+            return self.settings
+        elif attr in self.settings:
+            return self.settings[attr]
+        return None
+
+
 @contextmanager
 def patch_open():
     '''Patch open() to allow mocking both open() itself and the file that is