Clarify that cmdlib/ must be removed downgrading

Downgrading from 2.8 to a previous version will fail if the new cmdlib/
directory is not removed.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

diff --git a/UPGRADE b/UPGRADE
index 9b4f9a3..3fbc7da 100644 (file)
--- a/UPGRADE
+++ b/UPGRADE
@@ -131,6 +131,16 @@ revert the configuration **before** installing the old version.
    upgrading again.
 
 #. Install the old Ganeti version on all nodes
+
+   NB: in Ganeti 2.8, the ``cmdlib.py`` file was split into a series of files
+   contained in the ``cmdlib`` directory. If Ganeti is installed from sources
+   and not from a package, while downgrading Ganeti to a pre-2.8
+   version it is important to remember to remove the ``cmdlib`` directory
+   from the directory containing the Ganeti python files (which usually is
+   ``${PREFIX}/lib/python${VERSION}/dist-packages/ganeti``).
+   A simpler upgrade/downgrade procedure will be made available in future
+   versions of Ganeti.
+
 #. Restart daemons on all nodes::
 
     $ /etc/init.d/ganeti restart