doc: add timer-db description

doc/configuration.rst

@@ -110,7 +110,7 @@ See :ref:`keys`::
 If Knot DNS is compiled with the LMDB library, the server will be able to
 preserve slave zone timers across full server restarts. The zone expire,
 refresh, and flush timers are stored in a file-backed database in the
-:ref:`storage` directory in the ``timers`` subdirectory.
+directory configured with the :ref:`timer-db` option.
 
 Master configuration
 ====================

doc/reference.rst

@@ -769,6 +769,7 @@ The ``zones`` statement contains definition of zones served by Knot DNS.
 
     zones {
       [ zone_options ]
+      [ timer-db "string"; ]
       zone_id {
         file "string";
         [ xfr-in remote_id [, remote_id, ... ]; ]
@@ -882,8 +883,7 @@ Statement ``query_module`` takes a list of ``module_name
 ^^^^^^^^^^^
 
 Data directory for zones.  It is used to store zone files and journal
-files. If compiled with LMDB support, a database storing persistent zone
-event timers for slave zones will be created in the ``timers`` subdirectory.
+files.
 
 Value of ``storage`` set in ``zone`` section is relative to
 ``storage`` in ``zones`` section.
@@ -1053,6 +1053,16 @@ data in the form of a text or hexadecimal string.
 
 Default value: not set
 
+.. _timer-db:
+
+``timer-db``
+^^^^^^^^^^^^
+
+Specifies a path of the persisten timer database. The path can be specified
+as a relative path to the storage directory (:ref:`storage`).
+
+Default value: ``"timers"``
+
 .. _zones Example:
 
 ``zones`` Example

man/knot.conf.5.in

@@ -234,6 +234,10 @@ zones {
   # default: ${localstatedir}/lib/knot, configured with --with-storage
   storage "/var/lib/knot";
 
+  # Location of persistent zone timers. The path can be specified as
+  # a relative path to the global storage directory.
+  timer-db "timers";
+
   # Build differences from zone file changes. EXPERIMENTAL feature.
   # Possible values: on|off
   # Default value: off