Switch out zfs.autoSnapshot for sanoid

hosts/nixos/lapetus/services/zfs.nix

@@ -5,18 +5,44 @@
   services.zfs = {
     trim.enable = true;
     autoScrub.enable = true;
-
-    autoSnapshot = {
-      enable = true;
-
-      # -k -p is the default, and --utc is there to prevent timezone-related issues
-      autoSnapshot.flags = "-k -p --utc";
-    };
+    autoSnapshot = false; # We will configure this using sanoid
 
     # zed.enableMail = true;
   };
   # }}}
+  # {{{ Sanoid config 
+  # Sanoid allows me to configure snapshot frequency on a per-dataset basis.
+  services.sanoid = {
+    enable = true;
+
+    # {{{ Data
+    datasets.data = {
+      autosnap = true;
+      autoprune = true;
+      recursive = true;
+      yearly = 0;
+      monthly = 12;
+      weekly = 4;
+      daily = 7;
+      hourly = 24;
+    };
+    # }}}
+    # {{{ State
+    datasets.state = {
+      autosnap = true;
+      autoprune = true;
+      recursive = true;
+      yearly = 0;
+      monthly = 1;
+      weekly = 1;
+      daily = 3;
+      hourly = 6;
+    };
+    # }}}
+  };
+  # }}}
   # {{{ Zed email config
+  # Zed allows using email notifications for events
   sops.secrets.zed_smtp_pass.sopsFile = ../secrets.yaml;
   programs.msmtp.accounts.zed = {
     from = "zed@orbit.moonythm.dev";