Ok, I admit that I’m very, very late with this blog post: Trident 17.10 has actually been available for nearly six weeks!

It's hard to believe, but Trident has been out for almost a year now, and this release resolves issue #2, one of the earliest feature requests we received: scale the number of volumes we can support from a single ONTAP backend.

The original ontap-nas and ontap-san drivers both create an ONTAP flexible volume (FlexVol) when a user asks for a persistent volume. FlexVols are great because they are ONTAP's primary and most flexible unit of data management. All of the user-driven data management features that we’ll be bringing to you will be available to volumes crafted by these drivers, and for that reason they continue to be our recommended default.

The only downside with those drivers is that ONTAP can only host so many FlexVols. And sometimes all you need are volumes with ONTAP’s hallmark performance and reliability without all of the bells and whistles, and a whole lot of them. That’s where the new ontap-nas-economy driver comes in.

Scaling to Millions of Volumes

The ontap-nas-economy driver makes use of an ONTAP feature known as qtrees to carve out many persistent volumes in individual FlexVols. But don’t worry, we still manage the FlexVols too.

Like our other drivers, it was very important to us that this new driver not introduce any management overhead. To pull that off, we baked in the intelligence to know when a new FlexVol is needed to meet the demands of a particular volume, and we automated all of that.

The name "economy" was chosen specifically because it implies that the available feature set is limited compared to the standard drivers. In particular, you’ll note these differences between the drivers:

Most of these features are not yet available through the Kubernetes persistent volume framework, but as we surface them up, the economy driver will not be able to expose many of these capabilities on a volume granular basis. However, we did enable as many of the existing options as we could.

Together, these drivers allow Trident to wield ONTAP to provide both highly flexible and sophisticated volumes as well as massive scale. We expect many deployments will use them all, associating a higher cost with the class that creates volumes that provide more features, and a cheaper class that is backed by the economy driver.

Volume Encryption

Also in the 17.10 release is the option to specify volume encryption for ONTAP backends. More specifically, this leverages the NetApp Volume Encryption feature which was made available in ONTAP 9.1. Each PV which is provisioned using the ontap-nas and ontap-san drivers will have an encryption key unique to that volume. When using the ontap-nas-economy driver, the FlexVol pools that Trident creates will still have unique encryption keys, however the qtrees which share the same FlexVol will not be encrypted individually.

Enabling per-volume encryption can be done in the backend configuration file, just like the other options:

    "version": 1,
    "storageDriverName": "ontap-...",
    "defaults": {
      "encryption": true

That’s not all!

We also made the following notable improvements:

  • Added basic support for Kubernetes 1.8
  • Multi-pathing support was added to the SolidFire driver
  • xfs and ext3 are now supported file system types for all iSCSI drivers


This is just a subset of the fixes and enhancements in this release. And we’ve already started creating new beta releases with content slated for our 18.01 release. Be sure to keep an eye on Trident, things are moving fast!

Congratulations to the team on another fantastic release! If you have any questions about Trident or the changes in the 17.10 release, please leave us a comment below, reach out using Slack, or open an issue using GitHub.

About Andrew Sullivan

Andrew has worked in the information technology industry for over 10 years, with a rich history of database development, DevOps experience, and virtualization. He is currently focused on storage and virtualization automation, and driving simplicity into everyday workflows.

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