If an SQL database clone deletion fails immediately in NDB, the most likely cause is that the clone has been marked as Immutable. An immutable clone is protected from deletion to prevent accidental data loss, often set for critical development or testing environments. This protection must be explicitly removed by the administrator (e.g., via the NDB GUI or CLI) before the deletion can proceed.
Option A (A refresh operation is in progress) is incorrect because a refresh operation would delay but not immediately fail the deletion.
Option B (The clone has been marked as Immutable) is correct as immutability blocks deletion until changed.
Option C (The database was not marked as Offline before the operation) is incorrect because the offline state is not a prerequisite for clone deletion.
Option D (The database data drives are shared with other applications) is incorrect because shared drives might cause issues, but immutability is a more direct cause of immediate failure.
References
Nutanix Database Service (NDB) User Guide, Chapter 5: Configuring Time Machines, Section: Managing Clones and Deletion
Nutanix Support & Insights, Knowledge Base Article: "Troubleshooting Clone Deletion Failures in NDB"
Nutanix Certified Professional - Database Automation (NCP-DB) v7.5Blueprint, Section 5: Protect Databases Using Time Machine
