diff --git a/groups/all.py b/groups/all.py
index 29b18c3..f695a4b 100644
--- a/groups/all.py
+++ b/groups/all.py
@@ -3,32 +3,6 @@ groups['all'] = {
         r".*",
     },
     'subgroups': {
-        # This is only needed because we're overriding stuff in the group.
-        'home',
+        'linux',
     },
-    'bundles': {
-        'apt',
-        'backup-client',
-        'cron',
-        'hostname',
-        'openssh',
-        'postfix',
-        'sshmon',
-        'sudo',
-        'systemd',
-        'systemd-networkd',
-        'users',
-    },
-    'metadata': {
-        'apt': {
-            'unattended-upgrades': {
-                'mail': 'hostmaster@kunsmann.eu',
-            },
-        },
-        'backup-client': {
-            'server': 'franzi-home.kunbox.net:2022',
-        },
-    },
-    'pip_command': 'pip3',
 }
-
diff --git a/groups/locations.py b/groups/locations.py
index 4d46f32..c4fb7a7 100644
--- a/groups/locations.py
+++ b/groups/locations.py
@@ -63,9 +63,6 @@ groups['home'] = {
             # than our own domains.
             'relayhost': '[mx0.kunbox.net]:2525',
         },
-        'backup-client': {
-            'server': '172.19.138.20:22',
-        },
     },
 }
 
diff --git a/groups/os.py b/groups/os.py
index 98b384a..87fb50e 100644
--- a/groups/os.py
+++ b/groups/os.py
@@ -10,3 +10,55 @@ groups['raspberry'] = {
         },
     },
 }
+
+groups['linux'] = {
+    'subgroups': {
+        'debian',
+        'raspberry',
+    },
+    'bundles': {
+        'apt',
+        'backup-client',
+        'cron',
+        'hostname',
+        'openssh',
+        'postfix',
+        'sshmon',
+        'sudo',
+        'systemd',
+        'systemd-networkd',
+        'users',
+    },
+    'metadata': {
+        'apt': {
+            'unattended-upgrades': {
+                'mail': 'hostmaster@kunsmann.eu',
+            },
+        },
+        'backup-client': {
+            'server': 'franzi-home.kunbox.net:2022',
+        },
+    },
+    'pip_command': 'pip3',
+}
+
+groups['debian'] = {
+    'subgroups': {
+        'debian-buster',
+        'debian-bullseye',
+        'debian-sid',
+    },
+    'os': 'debian'
+}
+
+groups['debian-buster'] = {
+    'os_version': (10,)
+}
+
+groups['debian-bullseye'] = {
+    'os_version': (11,)
+}
+
+groups['debian-sid'] = {
+    'os_version': (11,)
+}
diff --git a/nodes/gce/bind01.py b/nodes/gce/bind01.py
index 394d63b..59d5697 100644
--- a/nodes/gce/bind01.py
+++ b/nodes/gce/bind01.py
@@ -8,6 +8,7 @@ nodes['gce.bind01'] = {
         'powerdnsadmin',
     },
     'groups': {
+        'debian-buster',
         'dns',
         'webserver',
     },
@@ -44,6 +45,4 @@ nodes['gce.bind01'] = {
             'ram': 1,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/gce/dns02.py b/nodes/gce/dns02.py
index 2fbb6ca..2db025e 100644
--- a/nodes/gce/dns02.py
+++ b/nodes/gce/dns02.py
@@ -5,6 +5,7 @@ nodes['gce.dns02'] = {
     'hostname': '35.187.109.249',
     'bundles': set(),
     'groups': {
+        'debian-buster',
         'dns',
     },
     'metadata': {
@@ -28,6 +29,4 @@ nodes['gce.dns02'] = {
             'ram': 1,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/gce/dns03.py b/nodes/gce/dns03.py
index 3259f17..aa28870 100644
--- a/nodes/gce/dns03.py
+++ b/nodes/gce/dns03.py
@@ -5,6 +5,7 @@ nodes['gce.dns03'] = {
     'hostname': '35.228.143.71',
     'bundles': set(),
     'groups': {
+        'debian-buster',
         'dns',
     },
     'metadata': {
@@ -28,6 +29,4 @@ nodes['gce.dns03'] = {
             'ram': 1,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/home/kodi-wohnzimmer.py b/nodes/home/kodi-wohnzimmer.py
index 9a662a4..8b7b46b 100644
--- a/nodes/home/kodi-wohnzimmer.py
+++ b/nodes/home/kodi-wohnzimmer.py
@@ -4,7 +4,9 @@ nodes['home.kodi-wohnzimmer'] = {
         'kodi',
         'nfs-client',
     },
-    'groups': set(),
+    'groups': {
+        'debian-buster',
+    },
     'metadata': {
         'interfaces': {
             'eth0': {
@@ -20,6 +22,9 @@ nodes['home.kodi-wohnzimmer'] = {
                 'vdpau-va-driver': {},
             },
         },
+        'backup-client': {
+            'server': '172.19.138.20:22',
+        },
         'nfs-client': {
             'mounts': {
                 'nas-storage': {
@@ -37,6 +42,4 @@ nodes['home.kodi-wohnzimmer'] = {
             'ram': 4,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/home/nas.py b/nodes/home/nas.py
index 56b0ec0..00cb5d1 100644
--- a/nodes/home/nas.py
+++ b/nodes/home/nas.py
@@ -7,7 +7,9 @@ nodes['home.nas'] = {
         'vmhost',
         'zfs',
     },
-    'groups': set(),
+    'groups': {
+        'debian-bullseye',
+    },
     'metadata': {
         'interfaces': {
             'br0.42': {
@@ -115,6 +117,4 @@ nodes['home.nas'] = {
             'ram': 16,
         },
     },
-    'os': 'debian',
-    'os_version': (11,),
 }
diff --git a/nodes/home/octoprint-vielschichtigkeit.py b/nodes/home/octoprint-vielschichtigkeit.py
index d8c8963..5a34d6d 100644
--- a/nodes/home/octoprint-vielschichtigkeit.py
+++ b/nodes/home/octoprint-vielschichtigkeit.py
@@ -5,6 +5,7 @@ nodes['home.octoprint-vielschichtigkeit'] = {
         'octoprint',
     },
     'groups': {
+        'debian-buster',
         'raspberry',
     },
     'metadata': {
@@ -17,6 +18,9 @@ nodes['home.octoprint-vielschichtigkeit'] = {
                 'mac': 'b8:27:eb:8e:0b:1d',
             },
         },
+        'backup-client': {
+            'server': '172.19.138.20:22',
+        },
         'nginx': {
             'use_ssl_for_all_connections': False,
             'vhosts': {
@@ -42,7 +46,4 @@ nodes['home.octoprint-vielschichtigkeit'] = {
             'ram': 1,
         },
     },
-    # This is a raspberry pi, but raspbian 64bit is plain debian.
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/home/router.py b/nodes/home/router.py
index 60999e8..72b36dd 100644
--- a/nodes/home/router.py
+++ b/nodes/home/router.py
@@ -12,7 +12,9 @@ nodes['home.router'] = {
         'vnstat',
         'wide-dhcp6c',
     },
-    'groups': set(),
+    'groups': {
+        'debian-buster',
+    },
     'metadata': {
         'interfaces': {
             'enp1s0.23': {
@@ -129,6 +131,4 @@ nodes['home.router'] = {
             },
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/htz-cloud/luther.py b/nodes/htz-cloud/luther.py
index 4071797..7c94798 100644
--- a/nodes/htz-cloud/luther.py
+++ b/nodes/htz-cloud/luther.py
@@ -5,6 +5,7 @@ nodes['htz-cloud.luther'] = {
         'zfs',
     },
     'groups': {
+        'debian-buster',
         'webserver',
     },
     'metadata': {
@@ -79,6 +80,4 @@ nodes['htz-cloud.luther'] = {
             'ram': 2,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/htz-cloud/pirmasens.py b/nodes/htz-cloud/pirmasens.py
index f6e08d6..6a1e8db 100644
--- a/nodes/htz-cloud/pirmasens.py
+++ b/nodes/htz-cloud/pirmasens.py
@@ -7,6 +7,7 @@ nodes['htz-cloud.pirmasens'] = {
         'rspamd',
     },
     'groups': {
+        'debian-buster',
         'webserver',
     },
     'metadata': {
@@ -74,6 +75,4 @@ nodes['htz-cloud.pirmasens'] = {
             'ram': 2,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/htz-cloud/sewfile.py b/nodes/htz-cloud/sewfile.py
index 404bde9..3ae5115 100644
--- a/nodes/htz-cloud/sewfile.py
+++ b/nodes/htz-cloud/sewfile.py
@@ -6,6 +6,7 @@ nodes['htz-cloud.sewfile'] = {
         'seafile',
     },
     'groups': {
+        'debian-buster',
         'webserver',
     },
     'metadata': {
@@ -38,6 +39,4 @@ nodes['htz-cloud.sewfile'] = {
             'ram': 2,
         }
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/htz/ex42-1048908.py b/nodes/htz/ex42-1048908.py
index 46e41c0..ed315dc 100644
--- a/nodes/htz/ex42-1048908.py
+++ b/nodes/htz/ex42-1048908.py
@@ -19,6 +19,7 @@ nodes['htz.ex42-1048908'] = {
         'voc-loudness-monitor',
     },
     'groups': {
+        'debian-buster',
         'webserver',
     },
     'metadata': {
@@ -344,6 +345,4 @@ nodes['htz.ex42-1048908'] = {
             'ram': 64,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/ovh/icinga2.py b/nodes/ovh/icinga2.py
index 50eaadb..6e604a1 100644
--- a/nodes/ovh/icinga2.py
+++ b/nodes/ovh/icinga2.py
@@ -6,6 +6,7 @@ nodes['ovh.icinga2'] = {
         'zfs',
     },
     'groups': {
+        'debian-buster',
         'webserver',
     },
     'metadata': {
@@ -64,6 +65,4 @@ nodes['ovh.icinga2'] = {
             'ram': 2,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }
diff --git a/nodes/rx300.py b/nodes/rx300.py
index cc83138..9d5a427 100644
--- a/nodes/rx300.py
+++ b/nodes/rx300.py
@@ -12,7 +12,9 @@ nodes['rx300'] = {
         'lldp', # TODO remove once this is no longer at home
         'zfs',
     },
-    'groups': set(),
+    'groups': {
+        'debian-buster',
+    },
     'metadata': {
         'interfaces': {
             'eth0': {
@@ -48,6 +50,4 @@ nodes['rx300'] = {
             'ram': 378,
         },
     },
-    'os': 'debian',
-    'os_version': (10,),
 }