You accidentally deleted several DNS entries from the Grid. How can you recover from this mistake with the least service disruption?
Correct Answer: D
Comprehensive and Detailed In-Depth Explanation:Accidentally deleting DNS entries (e.g., A records) in NIOS requires a recovery method that minimizes downtime and complexity. Here's the analysis:
* Recycle Bin Feature:NIOS includes a Recycle Bin (Data Management > DNS > Recycle Bin) that temporarily stores deleted objects (e.g., zones, records) unless permanently purged or the bin is disabled. Restoring from here is instantaneous and doesn't interrupt services.
* Options:
* A:Restoring from a backup (Grid > Grid Manager > Backup > Restore) replaces the entire database, requiring service restarts and potentially losing post-backup changes. High disruption.
Incorrect.
* B:Promoting a Grid Master Candidate (GMC) to Grid Master (GM) shifts control but doesn't recover deleted records-it's for GM failure, not data loss. Irrelevant. Incorrect.
* C:Forcing HA failover on the GM switches active/passive nodes but doesn't restore data, as both share the same database. No effect. Incorrect.
* D:Restoring from the Recycle Bin (select records > Restore) reverts the deletion with no service impact, assuming the bin is enabled (default in NIOS). Correct.
* Practical Example:In an INE lab, you'd delete an A record, navigate to the Recycle Bin, restore it, and verify DNS resolution-all without downtime, testing troubleshooting skills.
* Caveat:If the Recycle Bin is disabled or entries are purged, backup restoration (A) becomes necessary, but the question implies least disruption, favoring D.References:Infoblox NIOS Administrator Guide - Recycle Bin; INE Course Content: NIOS DDI DNS Troubleshooting.