Non-Disruptive Operations¶

NetApp’s ONTAP provides these benefits for non-disruptive operations:

• The movement of NetApp FlexVol volumes that contain Cinder volumes between different pools of disks (aggregates)
• The movement of Manila shares between different aggregates

In addition, using NetApp ONTAP, OpenStack environments gain these two key differentiators that would not be possible with volumes residing on Compute nodes:

• The ability to evacuate OpenStack instances from a Compute node for maintenance and upgrades.
• The ability to migrate Cinder volumes from one backend to another. The source and destination backend can be in the same cluster or in different clusters. The following is an example of migrating a Cinder volume that is in-use across two ONTAP hosts

Nova instance with an attached cinder volume. Pay particular attention to the value associated with the os-extended-volumes:volumes_attached field.

[~(keystone_admin)]# nova show ubuntu-instance
+--------------------------------------+--------------------------------------------------------+
| Property                             | Value                                                  |
+--------------------------------------+--------------------------------------------------------+
...
| name                                 | ubuntu-instance                                        |
| os-extended-volumes:volumes_attached | [{"id": "195d2581-d650-4618-ad65-a93ea0c3a89e"}]       |
| status                               | ACTIVE                                                 |
...

Issue the cinder show command against the volume id shown above, notice that the cinder volume is located at stlrx300s7-107@cinder-lma#10.250.118.49:/cinder_flexvol_OSTK02. This location is of the form compute node@backend#nfs server:/flexvol.

[~(keystone_admin)]# cinder show 195d2581-d650-4618-ad65-a93ea0c3a89e
+--------------------------------+----------------------------------------------------------------+
|            Property            |                             Value                              |
+--------------------------------+----------------------------------------------------------------+
...
|               id               |              195d2581-d650-4618-ad65-a93ea0c3a89e              |
|     os-vol-host-attr:host      | stlrx300s7-107@cinder-lma#10.250.118.49:/cinder_flexvol_OSTK02 |
|             status             |                             in-use                             |
...
+--------------------------------+----------------------------------------------------------------+

Get the list of available cinder pools, the target pool will be taken from this list

[~(keystone_admin)]# cinder get-pools
+----------+------------------------------------------------------------------------------+
| Property | Value                                                                        |
+----------+------------------------------------------------------------------------------+
| name     | stlrx300s7-107@cinder-lma#10.250.118.49:/cinder_flexvol_OSTK02               |
+----------+------------------------------------------------------------------------------+
+----------+------------------------------------------------------------------------------+
| Property | Value                                                                        |
+----------+------------------------------------------------------------------------------+
| name     | stlrx300s7-107@cinder-lmb#10.250.118.51:/cinder_flexvol_OSTK09               |
+----------+------------------------------------------------------------------------------+

Migrate the cinder volume identified above to stlrx300s7-107@cinder-lmb#10.250.118.51:/cinder_flexvol_OSTK09.

[~(keystone_admin)]# cinder migrate 195d2581-d650-4618-ad65-a93ea0c3a89e \
                                    stlrx300s7-107@cinder-lmb#10.250.118.51:/cinder_flexvol_OSTK09

Upon Completion of migration, note that the cinder volume has migrated as specified.

[~(keystone_admin)]# cinder show 195d2581-d650-4618-ad65-a93ea0c3a89e
+--------------------------------+----------------------------------------------------------------+
|            Property            |                             Value                              |
+--------------------------------+----------------------------------------------------------------+
...
|               id               |              195d2581-d650-4618-ad65-a93ea0c3a89e              |
|     os-vol-host-attr:host      | stlrx300s7-107@cinder-lmb#10.250.118.51:/cinder_flexvol_OSTK09 |
| os-vol-mig-status-attr:migstat |                            success                             |
|             status             |                             in-use                             |
...
+--------------------------------+----------------------------------------------------------------+