diff --git a/modules/ceph-common.nix b/modules/ceph-common.nix
new file mode 100644
index 0000000..6461da4
--- /dev/null
+++ b/modules/ceph-common.nix
@@ -0,0 +1,21 @@
+{ pkgs, ... }:
+{
+  services.ceph = {
+    enable = true;
+    global.fsid = "8a5ce363-be7d-417b-95ba-15acbb7f3a2e";
+    global.monHost = "10.0.69.192";
+    global.monInitialMembers = "mc4";
+  };
+
+  networking.firewall.allowedTCPPortRanges = [
+    {
+      from = 6800;
+      to = 7300;
+    }
+  ];
+
+  services.ceph.client.enable = true;
+  environment.systemPackages = [ pkgs.ceph ];
+}
+
+# vim: set et ts=2 sw=2 ai:
diff --git a/systems/mc5/configuration.nix b/systems/mc5/configuration.nix
index 056db7e..1e9c599 100644
--- a/systems/mc5/configuration.nix
+++ b/systems/mc5/configuration.nix
@@ -4,23 +4,17 @@
     [
       ./hardware-configuration.nix
       ./modules/generic.nix
+      ./modules/ceph-common.nix
     ];
-  system.stateVersion = "21.11";
+
   services.ceph = {
-    enable = true;
-    global.fsid = "be1051e6-ee13-44d6-a9a1-96cc36300e13";
-    global.monHost = "10.0.69.234";
-    global.monInitialMembers = "vpn";
-    #mds.enable = true;
-    #mds.daemons = [ "vpn"];
-    #mon.enable = true;
-    #mon.daemons = [ "vpn" ];
-    #osd.enable = true;
-    #osd.daemons = [ "0" ];
+    osd.enable = true;
+    osd.daemons = [ "0" ];
   };
 
-  services.ceph.client.enable = true;
-  environment.systemPackages = [ pkgs.ceph ];
+  documentation.enable = false;
+
+  system.stateVersion = "21.11";
 }
 
 # vim: set et ts=2 sw=2 ai: