Merge "Update Availability zone doc page"

1 files changed, 41 insertions, 15 deletions

diff --git a/doc/source/admin/availability-zones.rst b/doc/source/admin/availability-zones.rst
index ffe1be06f9..aff8a0ab31 100644
--- a/doc/source/admin/availability-zones.rst
+++ b/doc/source/admin/availability-zones.rst
@@ -118,11 +118,47 @@ Implications for moving servers
 
 There are several ways to move a server to another host: evacuate, resize,
 cold migrate, live migrate, and unshelve. Move operations typically go through
-the scheduler to pick the target host *unless* a target host is specified and
-the request forces the server to that host by bypassing the scheduler. Only
-evacuate and live migrate can forcefully bypass the scheduler and move a
-server to a specified host and even then it is highly recommended to *not*
-force and bypass the scheduler.
+the scheduler to pick the target host.
+
+Prior to API microversion 2.68, using older openstackclient (pre-5.5.0) and
+novaclient, it was possible to specify a target host and the request forces
+the server to that host by bypassing the scheduler. Only evacuate and live
+migrate can forcefully bypass the scheduler and move a server to specified host
+and even then it is highly recommended to *not* force and bypass a scheduler.
+
+- live migrate with force host (works with older openstackclients(pre-5.5.0):
+
+.. code-block:: console
+
+  $ openstack server migrate --live <host> <server>
+
+- live migrate without forcing:
+
+.. code-block:: console
+
+  $ openstack server migrate --live-migration --host <host> <server>
+
+While support for 'server evacuate' command to openstackclient was added
+in 5.5.3 and there it never exposed ability to force an evacuation, but
+it was previously possible with novaclient.
+
+- evacuate with force host:
+
+.. code-block:: console
+
+  $ nova evacuate --force <server> <host>
+
+- evacuate without forcing using novaclient:
+
+.. code-block:: console
+
+  $ nova evacuate 
+
+- evacuate without forcing using openstackclient:
+
+.. code-block:: console
+
+  $ openstack server evacuate --host <host> <server>
 
 With respect to availability zones, a server is restricted to a zone if:
 
@@ -150,16 +186,6 @@ If the server was not created in a specific zone then it is free to be moved
 to other zones, i.e. the :ref:`AvailabilityZoneFilter <AvailabilityZoneFilter>`
 is a no-op.
 
-Knowing this, it is dangerous to force a server to another host with evacuate
-or live migrate if the server is restricted to a zone and is then forced to
-move to a host in another zone, because that will create an inconsistency in
-the internal tracking of where that server should live and may require manually
-updating the database for that server. For example, if a user creates a server
-in zone A and then the admin force live migrates the server to zone B, and then
-the user resizes the server, the scheduler will try to move it back to zone A
-which may or may not work, e.g. if the admin deleted or renamed zone A in the
-interim.
-
 Resource affinity
 ~~~~~~~~~~~~~~~~~