doc: clarify use of location: in host spec

It wasn't clear that you can specify more than one element of the CRUSH hierarchy in a spec file, nor that it might be useful to do so (e.g. to ensure the host ends up beneath the default root).

So update the text to make it clearer, and similarly the example.

Signed-off-by: Matthew Vernon <mvernon@wikimedia.org>

diff --git a/doc/cephadm/host-management.rst b/doc/cephadm/host-management.rst
index 87f201fba65a5ed6e060954d263d16629789d585..7b8ca2cd5ba48f479f3ce1b459b522789f2cc87f 100644 (file)
--- a/doc/cephadm/host-management.rst
+++ b/doc/cephadm/host-management.rst
@@ -303,7 +303,10 @@ Setting the initial CRUSH location of host
 ==========================================
 
 Hosts can contain a ``location`` identifier which will instruct cephadm to 
-create a new CRUSH host located in the specified hierarchy.
+create a new CRUSH host bucket located in the specified hierarchy.
+You can specify more than one element of the tree when doing so (for
+instance if you want to ensure that the rack that a host is being
+added to is also added to the default bucket), for example:
 
 .. code-block:: yaml
 
@@ -311,6 +314,7 @@ create a new CRUSH host located in the specified hierarchy.
     hostname: node-00
     addr: 192.168.0.10
     location:
+      root: default
       rack: rack1
 
 .. note::