doc: add note about filter_logic

Signed-off-by: Joshua Schmid <jschmid@suse.de>
(cherry picked from commit 73475f3b396bf7892b921985b5b4fcf3e9732f42)

diff --git a/doc/cephadm/drivegroups.rst b/doc/cephadm/drivegroups.rst
index ae9b9205fc85416b75cb94a96712b23c3a36a32a..e4f9bd8c83dedf7327671f042defbcdac21d1e58 100644 (file)
--- a/doc/cephadm/drivegroups.rst
+++ b/doc/cephadm/drivegroups.rst
@@ -44,6 +44,15 @@ Since we want to have more complex setups, there are more filters than just the
 Filters
 =======
 
+.. note::
+   Filters are applied using a `AND` gate by default. This essentially means that a drive needs to fulfill all filter
+   criteria in order to get selected.
+   If you wish to change this behavior you can adjust this behavior by setting
+
+    `filter_logic: OR`  # valid arguments are `AND`, `OR`
+
+   in the OSD Specification.
+
 You can assign disks to certain groups by their attributes using filters.
 
 The attributes are based off of ceph-volume's disk query. You can retrieve the information