Created section about Live Migration in Nova (pick r6)

New section added to explain how to change live_migration_completion_timeout parameter and replacing Configure a Live Migration Completion Timeout in Nova
Fixed typo.

Signed-off-by: Elisamara Aoki Goncalves <elisamaraaoki.goncalves@windriver.com>
Change-Id: If025df41ea6a5e28a258a966f74249b116c26633

doc/source/system_configuration/openstack/configure-a-live-migration-parameters-in-nova-6154238dfc6d.rst

@@ -0,0 +1,108 @@
+.. _configure-a-live-migration-parameters-in-nova-6154238dfc6d:
+
+===========================================
+Configure Live Migration Parameters in Nova
+===========================================
+
+.. rubric:: |context|
+
+You can configure a maximum time for a live migration to complete and/or the
+maximum downtime target for live migration switchover.
+
+----------
+Parameters
+----------
+
+-   ``live_migration_completion_timeout``
+
+    Time to wait, in seconds, for live migration to successfully complete
+    transferring data before aborting the operation.
+
+    Value is per GiB of guest RAM + disk to be transferred, with a lower
+    boundary of 2 GiB. Set to 0 to disable timeouts.
+
+-   ``live_migration_downtime``
+
+    The target maximum period of time that Nova will require the |VM| to be
+    paused in order to complete the |VM| memory copy. If the transfer rate
+    slows down after the |VM| has been paused, this value can be exceeded by a
+    small amount of time, it will be rounded up to a minimum of 100ms.
+
+    You may increase this value if you want to allow live-migrations to
+    complete faster, or avoid ``live-migration`` timeout errors by allowing the
+    guest to be paused longer during the ``live-migration`` switch over.
+
+    Two additional ``live_migration_downtime_scope`` parameters can be
+    modified:
+
+    -   ``live_migration_downtime_steps``
+
+        Sets the total number of adjustment steps until
+        ``live_migration_downtime`` is reached. This will let nova increase
+        ``live_migration_downtime`` gradually until either the switchover has
+        been completed or the maximum value has been reached. The default is 10
+        steps.
+
+    -   ``live_migration_downtime_delay``
+
+        Sets the time interval between two adjustment steps in seconds. The
+        default is 75.
+
+.. rubric:: |proc|
+
+All the parameters can be modified using the Helm overrides for the |prod-os|
+application.
+
+#.  Create a yaml file containing the configuration update.
+
+    For example ``nova_override.yaml``:
+
+    .. code-block:: none
+
+        conf:
+            nova:
+                libvirt:
+                    live_migration_completion_timeout: 300
+                    live_migration_downtime: 600
+                    live_migration_downtime_steps: 12
+                    live_migration_downtime_delay: 50
+
+#.  Update the Helm overrides using the new configuration file.
+
+    .. code-block:: none
+
+        ~(keystone_admin)]$ system helm-override-update --values ./nova_override.yaml wr-openstack nova openstack --reuse-values
+
+#.  Confirm that the user override lists the correct live migration parameters.
+
+    .. code-block:: none
+
+        ~(keystone_admin)]$ system helm-override-show wr-openstack nova openstack
+
+#.  Apply the changes.
+
+    .. code-block:: none
+
+        ~(keystone_admin)]$ system application-apply wr-openstack
+
+.. rubric:: |result|
+
+If the live migration aborts because ``live_migration_completion_timeout`` has
+been exceeded, then the following message appears on the ``nova_compute`` logs:
+
+.. code-block:: none
+
+    WARNING nova.virt.libvirt.migration [-] [instance: 07b5842b-6324-4de0-973e-6d0ff18ef574] Live migration not completed after 300 seconds
+
+The default behavior is to abort the operation. You can change this action by
+configuring ``live_migration_timeout_action`` in your yaml file.
+
+For example:
+
+.. code-block:: none
+
+    live_migration_timeout_action: force_complete
+
+If it is set to ``force_complete``, the compute service will either pause the
+|VM| or trigger post-copy if post copy is enabled and available
+(``live_migration_permit_post_copy`` is set to True).

doc/source/system_configuration/openstack/configuring-a-live-migration-completion-timeout-in-nova.rst

@@ -1,57 +0,0 @@
-
-.. err1590511228224
-.. _configuring-a-live-migration-completion-timeout-in-nova:
-
-=====================================================
-Configure a Live Migration Completion Timeout in Nova
-=====================================================
-
-You can configure how long to allow for a compute live migration to
-complete before the operation is aborted.
-
-.. rubric:: |context|
-
-The following example applies a timeout of 300 seconds to all hosts.
-
-The same basic workflow of *creating an overrides file*, then
-*using it to update helm overrides for the application*, and finally
-*reapplying the application to make your changes effective* can be used
-to apply other Nova overrides globally.
-
-.. rubric:: |proc|
-
-#.  Create a yaml configuration file containing the configuration update.
-
-    .. code-block:: none
-
-        ~(keystone_admin)]$ cat << EOF > ./nova_override.yaml
-        conf:
-          nova:
-            libvirt:
-              live_migration_completion_timeout: 300
-        EOF
-
-
-#.  Update the Helm overrides using the new configuration file.
-
-    .. parsed-literal::
-
-        ~(keystone_admin)]$ system helm-override-update --reuse-values --values ./nova_override.yaml |prefix|-openstack nova openstack --reuse-values
-
-#.  Confirm that the user\_override lists the correct live migration completion timeout.
-
-    .. parsed-literal::
-
-        ~(keystone_admin)$ system helm-override-show |prefix|-openstack nova openstack
-
-    The output should include the following:
-
-    .. code-block:: none
-
-        live_migration_completion_timeout: 300
-
-#.  Apply the changes.
-
-    .. parsed-literal::
-
-        ~(keystone_admin)]$ system application-apply |prefix|-openstack

doc/source/system_configuration/openstack/index-sysconf-os-988a21c687cb.rst

@@ -16,7 +16,7 @@ Configure OpenStack Services Using Helm Chart Overrides
    :maxdepth: 1
 
    system-configuration-overview
-   configuring-a-live-migration-completion-timeout-in-nova
+   configure-a-live-migration-parameters-in-nova-6154238dfc6d
    configuring-a-pci-alias-in-nova
    configuring-the-rpc-response-timeout-in-cinder
    configure-the-nfs-backend-on-cinder-backup