diff --git a/modules/btrbk/default.nix b/modules/btrbk/default.nix
index ab557a0..00b5c04 100644
--- a/modules/btrbk/default.nix
+++ b/modules/btrbk/default.nix
@@ -1,3 +1,15 @@
+# For each instance, a service and timer will be created:
+#   systemctl list-unit-files | grep btrbk
+#   #=> btrbk-<instance-name>.service
+#   #=> btrbk-<instance-name>.timer
+#
+# If onCalendar is set to `null`, one can manually execute btrbk with
+#   sudo systemctl start btrbk-<instance-name>.service
+
+# Print generated systemd unit file
+#   cat "$(systemctl show -P FragmentPath btrbk-<instance-name>.service)"
+#   #=> ExecStart=/nix/store/53nvbl1c0w14524j7v3fpn9py31yi2hb-btrbk-0.32.6/bin/btrbk -c /etc/btrbk/local-backup.conf run
+
 { config, pkgs, ... }:
 let
   ssd-subvolumes = {
@@ -19,20 +31,10 @@ let
     # MediaKollektiv: 796 GiB
     "cloud.media-kollektiv.eu" = {};
   };
+  preserve-hourly = "24h 7d 4w 6m";
+  preserve-daily =      "7d 4w 6m";
 in
 {
-  # For each instance, a service and timer will be created:
-  #   systemctl list-unit-files | grep btrbk
-  #   #=> btrbk-<instance-name>.service
-  #   #=> btrbk-<instance-name>.timer
-  #
-  # If onCalendar is set to `null`, one can manually execute btrbk with
-  #   sudo systemctl start btrbk-<instance-name>.service
-
-  # Print generated systemd unit file
-  #   cat "$(systemctl show -P FragmentPath btrbk-<instance-name>.service)"
-  #   #=> ExecStart=/nix/store/53nvbl1c0w14524j7v3fpn9py31yi2hb-btrbk-0.32.6/bin/btrbk -c /etc/btrbk/local-backup.conf run
-
   services.btrbk = {
     extraPackages = [ pkgs.lz4 ];
     # Lowest scheduling priority.
@@ -49,14 +51,14 @@ in
           #stream_compress =  "lz4";
 
           snapshot_preserve_min = "2d";
-          snapshot_preserve =     "24h 7d 4w 6m";
+          snapshot_preserve = preserve-hourly;
 
           volume."/jc-data" = {
             snapshot_dir = "/snap";
             subvolume = ssd-subvolumes;
           };
           volume."/mnt/data/jc-data" = {
-            snapshot_dir = "/mnt/data/snap";
+            snapshot_dir = "/mnt/data/snap2";
             subvolume = hdd-subvolumes;
           };
         };
@@ -72,7 +74,7 @@ in
 
           # Create backups.
           target_preserve_min = "no";
-          target_preserve =     "7d 4w 6m";
+          target_preserve = preserve-daily;
 
           # Don't create or delete snapshots.
           snapshot_preserve_min = "all";
@@ -84,7 +86,7 @@ in
             subvolume = ssd-subvolumes;
           };
           volume."/mnt/data/jc-data" = {
-            snapshot_dir = "/mnt/data/snap";
+            snapshot_dir = "/mnt/data/snap2";
             target = "/mnt/backup/snap2";
             subvolume = hdd-subvolumes;
           };