Merge "docs: Add nova-volume volume_attachment refresh admin workflow"

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Zuul 2021-09-16 09:34:20 +00:00 committed by Gerrit Code Review
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@ -71,3 +71,146 @@ tests themselves, are defined in the `tempest repository`_.
.. _added support for multiattach volumes: https://specs.openstack.org/openstack/nova-specs/specs/queens/implemented/multi-attach-volume.html
.. _recorded overview and demo: https://www.youtube.com/watch?v=hZg6wqxdEHk
.. _tempest repository: http://codesearch.openstack.org/?q=CONF.compute_feature_enabled.volume_multiattach&i=nope&files=&repos=tempest
Managing volume attachments
---------------------------
During the lifecycle of an instance admins may need to check various aspects of
how a given volume is mapped both to an instance and the underlying compute
hosting the instance. This could even include refreshing different elements of
the attachment to ensure the latest configuration changes within the
environment have been applied.
Checking an existing attachment
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Existing volume attachments can be checked using the following
:python-openstackclient-doc:`OpenStack Client commands <cli/command-objects>`:
List all volume attachments for a given instance:
.. code-block:: shell
$ openstack server volume list 216f9481-4c9d-4530-b865-51cedfa4b8e7
+--------------------------------------+----------+--------------------------------------+--------------------------------------+
| ID | Device | Server ID | Volume ID |
+--------------------------------------+----------+--------------------------------------+--------------------------------------+
| 8b9b3491-f083-4485-8374-258372f3db35 | /dev/vdb | 216f9481-4c9d-4530-b865-51cedfa4b8e7 | 8b9b3491-f083-4485-8374-258372f3db35 |
+--------------------------------------+----------+--------------------------------------+--------------------------------------+
List all volume attachments for a given instance with the Cinder volume
attachment and Block Device Mapping UUIDs also listed with microversion >=2.89:
.. code-block:: shell
$ openstack --os-compute-api-version 2.89 server volume list 216f9481-4c9d-4530-b865-51cedfa4b8e7
+----------+--------------------------------------+--------------------------------------+------+------------------------+--------------------------------------+--------------------------------------+
| Device | Server ID | Volume ID | Tag | Delete On Termination? | Attachment ID | BlockDeviceMapping UUID |
+----------+--------------------------------------+--------------------------------------+------+------------------------+--------------------------------------+--------------------------------------+
| /dev/vdb | 216f9481-4c9d-4530-b865-51cedfa4b8e7 | 8b9b3491-f083-4485-8374-258372f3db35 | None | False | d338fb38-cfd5-461f-8753-145dcbdb6c78 | 4e957e6d-52f2-44da-8cf8-3f1ab755e26d |
+----------+--------------------------------------+--------------------------------------+------+------------------------+--------------------------------------+--------------------------------------+
List all Cinder volume attachments for a given volume from microversion >=
3.27:
.. code-block:: shell
$ openstack --os-volume-api-version 3.27 volume attachment list --volume-id 8b9b3491-f083-4485-8374-258372f3db35
+--------------------------------------+--------------------------------------+--------------------------------------+----------+
| ID | Volume ID | Server ID | Status |
+--------------------------------------+--------------------------------------+--------------------------------------+----------+
| d338fb38-cfd5-461f-8753-145dcbdb6c78 | 8b9b3491-f083-4485-8374-258372f3db35 | 216f9481-4c9d-4530-b865-51cedfa4b8e7 | attached |
+--------------------------------------+--------------------------------------+--------------------------------------+----------+
Show the details of a Cinder volume attachment from microversion >= 3.27:
.. code-block:: shell
$ openstack --os-volume-api-version 3.27 volume attachment show d338fb38-cfd5-461f-8753-145dcbdb6c78
+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ID | d338fb38-cfd5-461f-8753-145dcbdb6c78 |
| Volume ID | 8b9b3491-f083-4485-8374-258372f3db35 |
| Instance ID | 216f9481-4c9d-4530-b865-51cedfa4b8e7 |
| Status | attached |
| Attach Mode | rw |
| Attached At | 2021-09-14T13:03:38.000000 |
| Detached At | |
| Properties | access_mode='rw', attachment_id='d338fb38-cfd5-461f-8753-145dcbdb6c78', auth_method='CHAP', auth_password='4XyNNFV2TLPhKXoP', auth_username='jsBMQhWZJXupA4eWHLQG', cacheable='False', driver_volume_type='iscsi', encrypted='False', qos_specs=, target_discovered='False', target_iqn='iqn.2010-10.org.openstack:volume-8b9b3491-f083-4485-8374-258372f3db35', target_lun='0', target_portal='192.168.122.99:3260', volume_id='8b9b3491-f083-4485-8374-258372f3db35' |
+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
Refresh a volume attachment with nova-manage
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. versionadded:: 24.0.0 (Xena)
Admins may also refresh an existing volume attachment using the following
:program:`nova-manage` commands.
.. note::
Users can also refresh volume attachments by shelving and later unshelving
their instances. The following is an alternative to that workflow and
useful for admins when having to mass refresh attachments across an
environment.
.. note::
Future work will look into introducing an os-refresh admin API that will
include orchestrating the shutdown of an instance and refreshing volume
attachments among other things.
To begin the admin can use the `volume_attachment show` subcommand to dump
existing details of the attachment directly from the Nova database. This
includes the stashed `connection_info` not shared by the API.
.. code-block:: shell
$ nova-manage volume_attachment show 216f9481-4c9d-4530-b865-51cedfa4b8e7 8b9b3491-f083-4485-8374-258372f3db35 --json | jq .attachment_id
"d338fb38-cfd5-461f-8753-145dcbdb6c78"
If the stored `connection_info` or `attachment_id` are incorrect then the
admin may want to refresh the attachment to the compute host entirely by
recreating the Cinder volume attachment record(s) and pulling down fresh
`connection_info`. To do this we first need to ensure the instance is stopped:
.. code-block:: shell
$ openstack server stop 216f9481-4c9d-4530-b865-51cedfa4b8e7
Once stopped the host connector of the compute hosting the instance has to be
fetched using the `volume_attachment get_connector` subcommand:
.. code-block:: shell
root@compute $ nova-manage volume_attachment get_connector --json > connector.json
.. note::
Future work will remove this requirement and incorperate the gathering of
the host connector into the main refresh command. Unfortunatley until then
it must remain a seperate manual step.
We can then provide this connector to the `volume_attachment refresh`
subcommand. This command will connect to the compute, disconnect any host
volume connections, delete the existing Cinder volume attachment,
recreate the volume attachment and finally update Nova's database.
.. code-block:: shell
$ nova-manage volume_attachment refresh 216f9481-4c9d-4530-b865-51cedfa4b8e7 8b9b3491-f083-4485-8374-258372f3db35 connector.json
The Cinder volume attachment and connection_info stored in the Nova database
should now be updated:
.. code-block:: shell
$ nova-manage volume_attachment show 216f9481-4c9d-4530-b865-51cedfa4b8e7 8b9b3491-f083-4485-8374-258372f3db35 --json | jq .attachment_id
"9ce46f49-5cfc-4c6c-b2f0-0287540d3246"
The instance can then be restarted and the event list checked
.. code-block:: shell
$ openstack server start $instance