diff --git a/hosts/12kingdoms-youko/homelab-services/caddy.nix b/hosts/12kingdoms-youko/homelab-services/caddy.nix
index 1f404ebd..d4f540ee 100644
--- a/hosts/12kingdoms-youko/homelab-services/caddy.nix
+++ b/hosts/12kingdoms-youko/homelab-services/caddy.nix
@@ -22,7 +22,6 @@ in
     # Reload Caddy instead of restarting it when configuration file changes.
     enableReload = true;
     user = "caddy"; # User account under which caddy runs.
-    dataDir = "/persistent/apps/caddy";
     logDir = "/var/log/caddy";
 
     # Additional lines of configuration appended to the global config section of the Caddyfile.
@@ -41,7 +40,7 @@ in
 
     # https://caddyserver.com/docs/caddyfile/directives/file_server
     virtualHosts."file.writefor.fun".extraConfig = ''
-      root * /persistent/apps/caddy/fileserver/
+      root * /var/lib/caddy/fileserver/
       ${hostCommonConfig}
       file_server browse {
         hide .git
@@ -107,18 +106,10 @@ in
     443
   ];
 
-  # Create Directories
-  # https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html#Type
-  systemd.tmpfiles.rules = [
-    "d /persistent/apps/caddy/fileserver/ 0755 caddy caddy"
-    # directory for virtual machine's images
-    "d /persistent/apps/caddy/fileserver/vms 0755 caddy caddy"
-  ];
-
-  # Add all my wallpapers into /persistent/apps/caddy/fileserver/wallpapers
-  # Install the homepage-dashboard configuration files
+  # Serve the wallpapers from the file server. `mkdir -p` here covers the
+  # whole fileserver tree; caddy's dataDir itself is created by the module.
   system.activationScripts.installCaddyWallpapers = ''
-    mkdir -p /persistent/apps/caddy/fileserver/wallpapers
-    ${pkgs.rsync}/bin/rsync -avz --chmod=D2755,F644 ${wallpapers}/ /persistent/apps/caddy/fileserver/wallpapers/
+    mkdir -p /var/lib/caddy/fileserver/wallpapers
+    ${pkgs.rsync}/bin/rsync -avz --chmod=D2755,F644 ${wallpapers}/ /var/lib/caddy/fileserver/wallpapers/
   '';
 }
diff --git a/hosts/12kingdoms-youko/homelab-services/gitea.nix b/hosts/12kingdoms-youko/homelab-services/gitea.nix
index a03b1ed2..c65b424a 100644
--- a/hosts/12kingdoms-youko/homelab-services/gitea.nix
+++ b/hosts/12kingdoms-youko/homelab-services/gitea.nix
@@ -5,7 +5,6 @@
     enable = true;
     user = "gitea";
     group = "gitea";
-    stateDir = "/persistent/apps/gitea";
     appName = "Ryan Yin's Gitea Service";
     lfs.enable = true;
     # Enable a timer that runs gitea dump to generate backup-files of the current gitea database and repositories.
diff --git a/hosts/12kingdoms-youko/homelab-services/grafana/default.nix b/hosts/12kingdoms-youko/homelab-services/grafana/default.nix
index b6bbda51..5e1c24f0 100644
--- a/hosts/12kingdoms-youko/homelab-services/grafana/default.nix
+++ b/hosts/12kingdoms-youko/homelab-services/grafana/default.nix
@@ -13,7 +13,6 @@
 
   services.grafana = {
     enable = true;
-    dataDir = "/persistent/apps/grafana";
     provision.enable = true;
     settings = {
       server = {
diff --git a/hosts/12kingdoms-youko/homelab-services/monitoring/victoriametrics.nix b/hosts/12kingdoms-youko/homelab-services/monitoring/victoriametrics.nix
index a13cb1a7..1201c2d5 100644
--- a/hosts/12kingdoms-youko/homelab-services/monitoring/victoriametrics.nix
+++ b/hosts/12kingdoms-youko/homelab-services/monitoring/victoriametrics.nix
@@ -19,20 +19,19 @@ let
 in
 {
   # Since victoriametrics use DynamicUser, the user & group do not exists before the service starts.
-  # this group is used as a supplementary Unix group for the service to access our data dir(/persistent/apps/xxx)
+  # this group is used as a supplementary Unix group for the service to access our data dir under /var/lib
   users.groups.victoriametrics-data = { };
 
   # Workaround for victoriametrics to store data in another place
   # https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html#Type
   systemd.tmpfiles.rules = [
-    "d /persistent/apps/victoriametrics 0770 root victoriametrics-data - -"
+    "d /var/lib/victoriametrics 0770 root victoriametrics-data - -"
   ];
 
   # Symlinks do not work with DynamicUser, so we should use bind mount here.
   # https://github.com/systemd/systemd/issues/25097#issuecomment-1929074961
   systemd.services.victoriametrics.serviceConfig = {
     SupplementaryGroups = [ "victoriametrics-data" ];
-    BindPaths = [ "/persistent/apps/victoriametrics:/var/lib/victoriametrics:rbind" ];
   };
 
   # https://victoriametrics.io/docs/victoriametrics/latest/configuration/configuration/
diff --git a/hosts/12kingdoms-youko/homelab-services/oci-containers/homepage/default.nix b/hosts/12kingdoms-youko/homelab-services/oci-containers/homepage/default.nix
index 38050973..092a9450 100644
--- a/hosts/12kingdoms-youko/homelab-services/oci-containers/homepage/default.nix
+++ b/hosts/12kingdoms-youko/homelab-services/oci-containers/homepage/default.nix
@@ -5,7 +5,7 @@
 }:
 let
   user = "homepage";
-  configDir = "/persistent/apps/homepage-dashboard";
+  configDir = "/var/lib/homepage-dashboard";
 in
 {
   users.groups.${user} = { };
diff --git a/hosts/12kingdoms-youko/homelab-services/oci-containers/uptime-kuma/default.nix b/hosts/12kingdoms-youko/homelab-services/oci-containers/uptime-kuma/default.nix
index 33c8cfa5..02aaa2b2 100644
--- a/hosts/12kingdoms-youko/homelab-services/oci-containers/uptime-kuma/default.nix
+++ b/hosts/12kingdoms-youko/homelab-services/oci-containers/uptime-kuma/default.nix
@@ -1,37 +1,18 @@
-{ config, ... }:
-let
-  user = "kuma";
-  dataDir = "/persistent/apps/uptime-kuma";
-in
+{ ... }:
 {
-  users.groups.${user} = { };
-  users.users.${user} = {
-    group = user;
-    home = dataDir;
-    isSystemUser = true;
-  };
-
-  # Create Directories
-  # https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html#Type
-  systemd.tmpfiles.rules = [
-    "d ${dataDir} 0755 ${user} ${user}"
-  ];
-
   # https://github.com/NixOS/nixpkgs/blob/nixos-26.05/nixos/modules/virtualisation/oci-containers.nix
   virtualisation.oci-containers.containers = {
-    # check its logs via `journalctl -u podman-homepage`
+    # check its logs via `journalctl -u podman-uptime-kuma`
+    #
+    # The data lives in a podman *named volume*: podman creates it and takes
+    # the ownership from the image, so no host directory or tmpfiles rule is
+    # needed (the volume is under /var/lib/containers, which preservation
+    # already keeps).
     uptime-kuma = {
       hostname = "uptime-kuma";
       image = "docker.io/louislam/uptime-kuma:1";
       ports = [ "127.0.0.1:53350:3001" ];
-      # https://github.com/louislam/uptime-kuma/wiki/Environment-Variables
-      environment = {
-        # "PUID" = config.users.users.${user}.uid;
-        # "PGID" = config.users.groups.${user}.gid;
-      };
-      volumes = [
-        "${dataDir}:/app/data"
-      ];
+      volumes = [ "uptime-kuma-data:/app/data" ];
       autoStart = true;
     };
   };
diff --git a/hosts/12kingdoms-youko/homelab-services/postgresql.nix b/hosts/12kingdoms-youko/homelab-services/postgresql.nix
index ef3a1ffb..d3961afc 100644
--- a/hosts/12kingdoms-youko/homelab-services/postgresql.nix
+++ b/hosts/12kingdoms-youko/homelab-services/postgresql.nix
@@ -11,22 +11,14 @@ let
 
   user = "postgres"; # postgresql's default system user
   package = pkgs.postgresql_16;
-  dataDir = "/persistent/apps/postgresql/${package.psqlSchema}";
 in
 {
-  # Create Directories
-  # https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html#Type
-  systemd.tmpfiles.rules = [
-    "d /persistent/apps/postgresql 0700 ${user} ${user}"
-    "d ${dataDir} 0700 ${user} ${user}"
-  ];
-
   # https://wiki.nixos.org/wiki/PostgreSQL
   # https://search.nixos.org/options?channel=unstable&query=services.postgresql.
   # https://www.postgresql.org/docs/
   services.postgresql = {
     enable = true;
-    inherit package dataDir;
+    inherit package;
     # https://www.postgresql.org/docs/16/jit.html
     # JIT compilation is beneficial primarily for long-running CPU-bound queries.
     # Frequently these will be analytical queries. For short queries the added overhead
diff --git a/hosts/12kingdoms-youko/homelab-services/sftpgo.nix b/hosts/12kingdoms-youko/homelab-services/sftpgo.nix
index abe24760..afdaac68 100644
--- a/hosts/12kingdoms-youko/homelab-services/sftpgo.nix
+++ b/hosts/12kingdoms-youko/homelab-services/sftpgo.nix
@@ -1,7 +1,6 @@
 { config, lib, ... }:
 let
   user = "sftpgo";
-  dataDir = "/persistent/apps/sftpgo";
 in
 {
   # Read SFTPGO_DEFAULT_ADMIN_USERNAME and SFTPGO_DEFAULT_ADMIN_PASSWORD from a file
@@ -13,17 +12,9 @@ in
   # sftpgo can read/write files created by transmission, and vice versa.
   users.users.${user}.extraGroups = [ "fileshare" ];
 
-  # Create Directories
-  # https://www.freedesktop.org/software/systemd/man/latest/tmpfiles.d.html#Type
-  # Mode 2775: setgid ensures new files/dirs inherit the 'fileshare' group
-  # regardless of the creating process's primary group.
-  systemd.tmpfiles.rules = [
-    "d ${dataDir} 0755 ${user} ${user} -"
-  ];
-
   services.sftpgo = {
     enable = true;
-    inherit user dataDir;
+    inherit user;
     extraReadWriteDirs = [
       "/data/fileshare"
     ];