From Zed cycle, NetApp drivers NFS, iSCSI and FCP have the option to request ONTAP operations through REST API. By default, the drivers keep working as before using ZAPI communication. If desired, the REST communication can be selected. However, this REST client still relies on ZAPI calls for consistency group snapshot operation.
The NVMe/TCP ONTAP driver has been delivered with Antelope cycle. This driver only runs with REST communication mode and it does not require enabling this mode as other driver does.
Important
The REST mode still relies on ZAPI for some calls, so the ONTAP
administrative user account must have access for running ONTAPI
application even when using the drivers with REST communication mode.
Important
The drivers can only be configured with REST communication with ONTAP storage 9.11.1 or newer.
Caution
Enabling ONTAP REST client changes the behavior of QoS specs. Earlier, QoS values could be represented in BPS (bytes per second), but now REST client only supports integer values represented in MBPS (Megabytes per second). It means that though the operators specify the QoS value in BPS, it will be converted to MBPS and rounded up. It only affects new volumes.
To enable REST client for the NetApp ONTAP drivers (iSCSI, FCP or NFS), the following option should be added to the appropriate NetApp stanza in the Cinder configuration file (cinder.conf).
[myONTAPBackend]
netapp_use_legacy_client = False
Note
Operations running with REST client may take some time to be finished. The
option netapp_async_rest_timeout configures the time to wait for the
completion. Default is 60 seconds.
This document is licensed under Apache 2.0 license.