diff --git a/plugin/plugin.j2 b/plugin/plugin.j2
index 5756391..abb57e7 100644
--- a/plugin/plugin.j2
+++ b/plugin/plugin.j2
@@ -93,16 +93,13 @@ fi
 mkdir -p /var/tmp/fanctrlplus2
 rm -f /var/tmp/fanctrlplus2/*
 pkill -f "/usr/local/emhttp/plugins/fanctrlplus2/scripts/array_monitor.sh"
+rm -f /boot/config/plugins/fanctrlplus2/.config.lock # the lock now lives in /var/run
 
+# start() launches array_monitor.sh (pgrep-guarded); do not start it again here.
 if [[ -x "$dst" ]]; then
   "$dst" restart
 fi
 
-script="/usr/local/emhttp/plugins/fanctrlplus2/scripts/array_monitor.sh"
-if [[ -x "$script" ]]; then
-  nohup "$script" >/dev/null 2>&1 &
-fi
-
 echo ""
 echo "------------------------------------------------"
 echo " FanCtrl Plus 2 is installed."
diff --git a/src/usr/local/emhttp/plugins/fanctrlplus2/include/ConfigBackup.php b/src/usr/local/emhttp/plugins/fanctrlplus2/include/ConfigBackup.php
index 823ce64..a1dbc56 100644
--- a/src/usr/local/emhttp/plugins/fanctrlplus2/include/ConfigBackup.php
+++ b/src/usr/local/emhttp/plugins/fanctrlplus2/include/ConfigBackup.php
@@ -5,7 +5,8 @@
 
 function fcp_config_lock(string $dir, int $mode = LOCK_EX) {
     if (is_link($dir) || (!is_dir($dir) && !@mkdir($dir, 0700, true))) throw new RuntimeException('Configuration directory is unavailable.');
-    $path = "$dir/.config.lock";
+    // In RAM, so taking the lock never writes to the flash drive (#19). Shared with array_monitor.sh.
+    $path = getenv('FCP_CONFIG_LOCK') ?: '/var/run/fanctrlplus2.config.lock';
     if (is_link($path) || (file_exists($path) && !is_file($path))) throw new RuntimeException('Unsafe configuration lock.');
     // Service daemons must never inherit the request's flock descriptor.
     $lock = @fopen($path, 'ce');
diff --git a/src/usr/local/emhttp/plugins/fanctrlplus2/scripts/array_monitor.sh b/src/usr/local/emhttp/plugins/fanctrlplus2/scripts/array_monitor.sh
index 2360543..0f737f1 100644
--- a/src/usr/local/emhttp/plugins/fanctrlplus2/scripts/array_monitor.sh
+++ b/src/usr/local/emhttp/plugins/fanctrlplus2/scripts/array_monitor.sh
@@ -7,7 +7,7 @@ rc_script="/etc/rc.d/rc.${plugin}"
 pidfile="/var/run/fanctrlplus2.user_stopped"
 # Shared with the settings page; a configuration restore holds it while it
 # swaps files.
-config_lock="/boot/config/plugins/${plugin}/.config.lock"
+config_lock="/var/run/${plugin}.config.lock"
 
 last_md_state=""
 last_fanctrl_state=0
@@ -45,7 +45,7 @@ while true; do
         log "FanCtrlPlus not running after array start → launching"
         "$rc_script" start 9>&-
       fi
-    ) 9>"$config_lock"
+    ) 9>>"$config_lock" # append: '>' would rewrite the file on the flash drive every pass
   fi
 
   sleep "$CHECK_INTERVAL"
diff --git a/tests/config_backup_test.php b/tests/config_backup_test.php
index f14658c..8402aa1 100644
--- a/tests/config_backup_test.php
+++ b/tests/config_backup_test.php
@@ -4,6 +4,7 @@
 require_once $module;
 $root = sys_get_temp_dir().'/fcp_backup_'.getmypid();
 mkdir($root, 0700, true);
+putenv("FCP_CONFIG_LOCK=$root/.config.lock");
 $failures = [];
 $check = function ($condition, string $message) use (&$failures) { if (!$condition) $failures[] = $message; };
 $fan = <<<'CFG'