Azure PostgreSQL Lesson Learned #10: Why PITR Networking Rules Matter
Co‑authored with angesalsaa Symptoms Customer attempted to restore a server configured with public access into a private virtual network. Restore operation failed with an error indicating unsupported configuration. Root Cause Azure enforces strict networking rules during PITR to maintain security and consistency: Public access servers can only be restored to public access. Private access servers can be restored to the same virtual network or a different virtual network, but not to public access. Why This Happens Networking mode is tied to the original server configuration. Mixing public and private access during restore could expose sensitive data or break connectivity assumptions. Contributing Factors Customer assumed PITR could switch networking modes. No prior review of Azure documentation on restore limitations. Specific Conditions We Observed Source server: Private access with VNet integration. Target restore: Attempted to switch to public access. Operational Checks Before initiating PITR: Confirm the source server’s networking mode (Public vs Private). Review restore options in the Azure portal → Restore. Mitigation Goal: Align restore strategy with networking rules. If source is Public: Restore only to Public access. If source is Private: Restore to same or different VNet (within the same region). Post-Resolution Customer successfully restored to a different VNet after adjusting expectations. Prevention & Best Practices Document networking mode for all PostgreSQL servers. Train teams on PITR limitations before disaster recovery drills. Avoid assumptions always check official guidance. Why This Matters Ignoring these rules can delay recovery during critical incidents. Knowing the constraints upfront ensures faster restores and compliance with security policies. Key Takeaways Issue: PITR does not allow switching between Public and Private access. Fix: Restore within the same networking category as the source server. References Backup and Restore in Azure Database for PostgreSQL Flexible Server
