--- a/udev.conf
+++ b/udev.conf
@@ -1,4 +1,7 @@
 # The initial syslog(3) priority: "err", "info", "debug" or its
 # numerical equivalent. For runtime debugging, the daemons internal
 # state can be changed with: "udevadm control --log-priority=<value>".
+#
+# udevd is started in the initramfs, so when this file is modified the
+# initramfs should be rebuilt.
 udev_log="err"
