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>
(cherry picked from commit 2366391ccec0fb6d8a1c159d6e3cdf5ff4f1d603)

diff --git a/doc/cephadm/host-management.rst b/doc/cephadm/host-management.rst
index eb83efb24b9507f2cae5be01cbb75a753ddd0897..9c47486d6473519630da302b766c443c03fc28c1 100644 (file)
--- a/doc/cephadm/host-management.rst
+++ b/doc/cephadm/host-management.rst
@@ -311,7 +311,10 @@ 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
 
@@ -319,6 +322,7 @@ create a new CRUSH host located in the specified hierarchy.
     hostname: node-00
     addr: 192.168.0.10
     location:
+      root: default
       rack: rack1
 
 .. note::