Issue/Introduction

This article helps troubleshoot cases where an individual snapshot created by a ZSphere backup cannot be deleted from a UI snapshot group.

Symptoms

• The UI snapshot group page does not show an individual volume snapshot created by backup software or the CLI.
• Storage capacity or a cloning task indicates that a volume snapshot still exists, and the user wants to delete the individual snapshot.
• The volume snapshot uuid can be queried through the CLI or API, but the UI has no corresponding snapshot group.

Environment

• Product: ZVF
• Version: 4.10.x
• Component: ZSphere
• Affected object: snapshot or backup
• Scenario: For snapshot and backup issues, confirm the current version, deployment type, storage type, and operation timeline.

Possible causes

• The backup software, migration, cloning task, or CLI created a volume snapshot object that does not necessarily belong to the UI snapshot group view.
• The snapshot is still required by a backup chain, cloning chain, image creation task, or reclamation or rollback chain.
• Snapshot group deletion and individual volume snapshot deletion operate on different object levels, and direct deletion might damage the backup chain.

Resolution

Perform the following checks in order, and record the affected object, occurrence time, complete error message, and current status.

1. Confirm the snapshot source: a UI snapshot group, backup software, a migration or cloning task, or manual CLI or API creation.
2. Record volumeUuid, volumeSnapshotUuid, virtual machine UUID, backup task ID, and creation time.
3. Use read-only queries to confirm whether the snapshot has children or is referenced by a backup task or image creation task.
4. If the snapshot was created by a backup system, prioritize deletion and chain cleanup through that backup system. If deletion through the ZSphere CLI or API is required, ZStack official technical support must confirm the availability of managed interfaces such as DeleteVolumeSnapshot.
5. Do not delete the snapshot object directly from underlying storage before dependency relationships are confirmed. Before production handling, back up the database and request a change window.

Remediation

1. Delete the snapshot and clean up its snapshot chain through the backup system that created it.
2. When deletion through the ZSphere CLI or API is required, first ask ZStack official technical support to confirm the managed interface and dependencies, and then perform the deletion.

Verification

• Snapshot references have been cleaned up, and related backup, cloning, and image tasks are unaffected.
• Snapshot information is consistent in the UI, CLI or API, and underlying storage, and capacity consumption returns to the expected state.