Feature Request: prune persistent volumes

[tobwen]

Summary

Add support for "persistent" volumes that are excluded from podman system prune by default, requiring explicit confirmation or a special flag to delete them.

Description

Currently, all volumes are treated equally by podman system prune, which can accidentally delete important volumes containing valuable data. Users need a way to protect certain volumes from accidental deletion while maintaining the ability to clean up temporary volumes.

Proposed Solution

1. Add a --persistent flag to podman volume create:

   podman volume create --persistent my_important_data

2. Modify prune behavior:

   • Persistent volumes are skipped by default in podman system prune
   • Add --include-persistent flag to override this protection
   • Alternative: Interactive confirmation when persistent volumes exist

3. Add visibility features:

   podman volume inspect # shows "Persistent": true/false
   podman volume ls      # adds PERSISTENT column

Use Cases

• Database volumes that should never be accidentally purged
• Configuration volumes containing important state
• Development environments mixing long-lived and temporary volumes

Alternatives Considered

• Using labels (not respected by prune)
• Manual volume management (error-prone)
• External documentation/remembering (ineffective)

Additional Context

This would providing more granular control in what gets pruned. Backward compatibility would be maintained by treating existing volumes as non-persistent.

[Luap99]

Closing as dup

[tobwen]

I know it got closed, but I wanted to give it a try: https://github.com/tobwen/podman/tree/podman-26807