Data storage

The DSRI uses OpenShift Container Storage (OCS) based on Ceph. Three types of storage are available:

• Ephemeral storage - storage bound to the pod. Data is lost when the pod is restarted or deleted. Useful for quick testing as it does not require creating a persistent volume.
• Dynamic storage - persistent storage created automatically when starting an application from a template. Can also be created manually via the DSRI web UI.
• Persistent storage - a persistent volume you create and manage yourself. Data survives pod restarts. There are no backups on the DSRI, so always keep a copy of your data elsewhere.

caution

A Persistent Volume Claim (PVC) is only accessible within the project where it was created.

Storage limit per PVC

PVC storage requests are limited to a maximum of 10Ti per PVC. If you need more, contact us.

Create the Persistent Storage (PVC)

1. Switch to the Administrator view.
2. Go to Storage > Persistent Volume Claims.
3. Click Create Persistent Volume Claim.
4. Choose the storage class. The default is ocs-storagecluster-ceph-rbd (block storage). Change this to ocs-storagecluster-cephfs if you want to bind multiple pods to the same PVC.
5. Provide a unique name for the PVC, starting with pvc- (e.g. pvc-filebrowser).
6. Select the access mode and storage size:

Access Mode	Abbreviation	Description
ReadWriteOnce	RWO	Mounted as read-write by a single node.
ReadOnlyMany	ROX	Mounted as read-only by many nodes.
ReadWriteMany	RWX	Mounted as read-write by many nodes. Use this when possible.

7. Click Create.

info

Use ReadWriteMany (RWX) when possible. If a node fails, RWO volumes cannot be remounted on another node until the pod is force-deleted.

info

Some templates such as JupyterLab automatically create a persistent volume when instantiated.

Connect an Existing Persistent Storage (PVC)

To attach an existing PVC to an application:

1. On the Topology page, click on your application.
2. Click Actions > Add Storage.
3. Select Use Existing Claim and choose the PVC.
4. Set the Mount Path.
5. Click Save.

This is also how you connect multiple applications to the same storage.

Expand an Existing Persistent Storage (PVC)

1. Switch to the Administrator view.
2. Go to Storage > Persistent Volume Claims.
3. Click the three dots (⋮) next to the PVC you want to expand.
4. Click Expand PVC.
5. Enter the new size and click Expand. It can take up to 2 minutes to complete.

Use dynamic storage

Dynamic storage can be created manually:

1. In your project, go to Storage in the left sidebar.
2. Click Create Storage.
3. Set the storage class to ocs-storagecluster-cephfs.
4. Choose an access mode:
   • Single User (RWO) - only you can read and write.
   • Shared Access (RWX) - all users with project access can read and write.
   • Read Only (ROX) - all users with project access can read.

Ephemeral storage

danger

Ephemeral storage is currently disabled by default as it was causing data loss for users.

When creating a pod without persistent storage, OpenShift uses ephemeral storage bound to the pod, and be aware that the data is lost when the pod is deleted. This can be sufficient for quick testing but is not recommended for any data you want to keep.