conf: more comments about use_lvmetad + autoactivation relation

diff --git a/conf/example.conf.in b/conf/example.conf.in
index 78c69e525a778d5bcf45513da61f10af12433f7b..b99f010406671252521a35c7a6d2de480ad21274 100644 (file)
--- a/conf/example.conf.in
+++ b/conf/example.conf.in
@@ -541,15 +541,24 @@ global {
 
     # Whether to use (trust) a running instance of lvmetad. If this is set to
     # 0, all commands fall back to the usual scanning mechanisms. When set to 1
-    # *and* when lvmetad is running (it is not auto-started), the volume group
-    # metadata and PV state flags are obtained from the lvmetad instance and no
-    # scanning is done by the individual commands. In a setup with lvmetad,
-    # lvmetad udev rules *must* be set up for LVM to work correctly. Without
-    # proper udev rules, all changes in block device configuration will be
-    # *ignored* until a manual 'pvscan --cache' is performed.
+    # *and* when lvmetad is running (automatically instantiated by making use of
+    # systemd's socket-based service activation or run as an initscripts service
+    # or run manually), the volume group metadata and PV state flags are obtained
+    # from the lvmetad instance and no scanning is done by the individual
+    # commands. In a setup with lvmetad, lvmetad udev rules *must* be set up for
+    # LVM to work correctly. Without proper udev rules, all changes in block
+    # device configuration will be *ignored* until a manual 'pvscan --cache'
+    # is performed. These rules are installed by default.
     #
     # If lvmetad has been running while use_lvmetad was 0, it MUST be stopped
     # before changing use_lvmetad to 1 and started again afterwards.
+    #
+    # If using lvmetad, the volume activation is also switched to automatic
+    # event-based mode. In this mode, the volumes are activated based on
+    # incoming udev events that automatically inform lvmetad about new PVs
+    # that appear in the system. Once the VG is complete (all the PVs are
+    # present), it is auto-activated. The activation/auto_activation_volume_list
+    # setting controls which volumes are auto-activated (all by default).
     use_lvmetad = 0
 
     # Full path of the utility called to check that a thin metadata device