Move indexDir option to the mailserver scopelewo/indexDir

This option has been initially in the mailserver.fullTextSearch
scope. However, this option modifies the location of all index files
of dovecot and not only those used by the full text search feature. It
is then more relevant to have this option in the mailserver top level
scope.

Moreover, the default option has been changed to null in order to keep
existing index files where they are: changing the index location means
recreating all index files. The fts documentation however recommend to
change this default location when enabling the fts feature.

1 files changed, 11 insertions, 3 deletions

diff --git a/docs/fts.rst b/docs/fts.rst
index cf7b561..aed2cba 100644
--- a/docs/fts.rst
+++ b/docs/fts.rst
@@ -38,9 +38,17 @@ issues a search query, so latency will be high.
 Resource requirements
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
-Indices can take more disk space than the emails themselves. By default, they
-are kept in a different location (``/var/lib/dovecot/fts_xapian``) than emails
-so that you can backup emails without indices.
+Indices created by the full text search feature can take more disk
+space than the emails themselves. By default, they are kept in the
+emails location. When enabling the full text search feature, it is
+recommended to move indices in a different location, such as
+(``/var/lib/docecot/indices/%d/%n``) by using the option
+``mailserver.indexDir``.
+
+.. warning::
+
+   When the value of the ``indexDir`` option is changed, all dovecot
+   indices needs to be recreated: clients would need to resynchronize.
 
 Indexation itself is rather resouces intensive, in CPU, and for emails with
 large headers, in memory as well. Initial indexation of existing emails can take