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Flexible Disks

· 3 min read
Yifan Lin
Yifan Lin
Software Engineer
Michael McQuade
Michael McQuade
Director of Engineering

We're excited to tell you about a new set of disk features we've been adding over the past several months.

Starting today, you can add optional disks to your clusters on all three cloud service providers (CSPs). Disks are created either by creating creating a persistent disk or inlining configuration directly into your cluster definition.

Disks support:

  • Specifying their size in GiB or GB, depending on the CSP.
  • Specifying a type, as offered by the CSP. This controls the performance characteristics of the disk.
  • Optionally, restoring from a snapshot.
  • Optionally, exporting the disk to the cluster via NFS.

To get started, you can head to the Disks page and create a new persistent disk, configure it, then start it the same way you would a cluster. The disk will be provisioned in a few moments, and you'll be able to attach it to your cluster by modifying your cluster's definition to specify the mount path.

Screenshot of new Disks page.

Alternatively, inlining is a new way of defining an ephemeral storage. Instead of maintaining configuration separately from the cluster, the configuration is stored with the cluster and so when you share the cluster configuration to the marketplace, it will contain the disk configuration as well.

Inline disks will be created when the cluster starts. All disks are automatically attached to the controller node of the cluster. Disks are automatically formatted as ext4 and mounted at the path specified in the configuration specified.

Use Cases​

Persistent Disks​

One advantage of creating a persistent disk is that its lifecycle is separate from the cluster. This means you can stop and start your cluster without losing the data on the disk. This can help reduce costs by allowing you to stop your cluster when you're not using it, and start it back up when you need it.

NFS Exports and Snapshots​

A popular use case we targeted is the creation of disks from snapshots. This is particularly useful with inline disks.

You can install modules and applications onto a disk, then snapshot the disk. When creating a disk, you can select a snapshot to restore. Then, when you are attaching the disk to the controller, choose the option to NFS export the disk. The controller and the compute nodes of the cluster will all have access to the apps you installed on the disk at the same path.

Adding Capacity​

Finally, you can attach and detach disks to the controller while it is running. This can be useful for moving data around or for adding additional storage to the controller.

Coming Soon​

Within the next few weeks, we will be adding the ability to define additional inline disks at the partition level. Please look forward to more news on that in a later post!