Choosing a driver¶
To create and use an ONTAP backend, you will need:
- A supported ONTAP storage system
- Choose the ONTAP storage driver that you want to use
- Complete ONTAP backend preparation for the driver of your choice
- Authentication credentials (username/password or certificate) to an ONTAP SVM with appropriate access
Trident provides 5 unique storage drivers for communicating with ONTAP clusters. Each driver handles the creation of volumes and access control differently and their capabilities are detailed in this section.
|Driver||Protocol||VolumeMode||Access Modes Supported||File Systems Supported|
|ontap-san||iSCSI||Block||RWO,ROX,RWX||No Filesystem. Raw block device|
|ontap-san-economy||iSCSI||Block||RWO,ROX,RWX||No Filesystem. Raw block device|
- ONTAP backends can be authenticated by one of two means:
- Login credentials for a security role [username/password] OR
- Certificated-based, using the private key and the certificate that is installed on the ONTAP cluster.
Users can update existing backends to move from one authentication mode to the other
tridentctl update backend.
ontap-san-economy drivers support the
Block volumeModes. Users can choose to create a raw block volume with
no file system (or) have Trident create a volume with a file system. For the
fsType is specified through the Storage Class.
kind: StorageClass apiVersion: storage.k8s.io/v1 metadata: name: netapp-san-economy provisioner: csi.trident.netapp.io parameters: backendType: "ontap-san-economy" fsType: "ext4"
Please refer to the NetApp Hardware Universe for up-to-date information on volume limits for your storage cluster. Based on the number of nodes, the platform and the version of ONTAP being used, these limits will vary.
ontap-san drivers create an ONTAP FlexVol for each
PV. If your persistent volume requirements fit within
that limitation, those drivers are the preferred solution due to the granular
data management capabilities they afford.
If you need more persistent volumes than may be accommodated by the FlexVol
limits, choose the
ontap-nas-economy or the
ontap-nas-economy driver creates PVs as ONTAP
Qtrees within a pool of automatically managed FlexVols. Qtrees offer far
greater scaling at the expense of granular data management features. Users can
configure the number of Qtrees created per FlexVol (between 50 and 300) for a
backend. By default, a FlexVol created by Trident can contain 200 Qtrees.
ontap-san-economy driver creates PVs as ONTAP LUNs within a pool of
automatically managed FlexVols. Each PV maps to an ONTAP LUN and this driver offers
higher scalability for SAN workloads. Since PVs map to LUNs
within shared FlexVols, Kubernetes VolumeSnapshots are created using ONTAP’s FlexClone
technology. FlexClone LUNs and their parent LUNs share blocks, minimizing disk usage.
ontap-nas-flexgroup driver to increase parallelism to a single volume
that can grow into the petabyte range with billions of files. Some ideal use cases
for FlexGroups include AI/ML/DL, big data and analytics, software builds, streaming,
file repositories, etc. Trident uses all aggregates assigned to an SVM when
provisioning a FlexGroup Volume. FlexGroup support in Trident also has the following
- Requires ONTAP version 9.2 or greater.
- With ONTAP 9.7, FlexGroups work with NFSv4. For ONTAP clusters that are running
9.6 and below, NFSv3 must be used (required to set
mountOptions: ["nfsvers=3"]in the Kubernetes storage class).
- When using NFSv3, it is recommended to enable the 64-bit NFSv3 identifiers for the SVM.
- The minimum recommended FlexGroup size is 100GB.
- Cloning FlexGroup volumes is supported with ONTAP 9.7 and above.
For information regarding FlexGroups and workloads that are appropriate for FlexGroups see the NetApp FlexGroup Volume - Best Practices and Implementation Guide.