Shared Volumes

A shared volume lets several apps in the same project mount the same persistent storage. This is useful when two workloads must read and write the same files, for example an app and a companion service.

Requirements

A volume can be shared only when:

• Its access mode is ReadWriteMany (RWX).
• Its storage class is not local-path.
• It is not itself already a shared mount.

If your volume does not meet these requirements, edit it in Settings → Storage → Volumes. Access mode cannot be changed after creation, so an RWO or local-path volume must be recreated. See Volumes.

Allow other apps to attach a volume

1. Open the app that owns the volume in the Project Canvas and go to Settings → Storage.
2. In the Volumes card, edit the volume.
3. Enable Allow other apps to attach this volume.
4. Click Save, then Deploy.

Attach a shared volume to another app

1. Open the other app and go to Settings → Storage.
2. Click Add Shared Volume.
3. In the Mount Shared Volume dialog:
   • Select Shared Volume — pick the volume from the list (shown as <App name> - <mount path> (<size> MB)).
   • Mount Path in This Container — where to mount it in this app.
4. Click Mount Shared Volume, then Deploy.

The size, access mode, and storage class are inherited from the source volume and shown as read-only.

Detach a shared volume

Open the app, go to Settings → Storage, and remove the shared mount with Detach Volume. The data remains on the source volume.

Related

• Volumes
• File Browser
• Networking & Policies — connecting apps to each other