Recover a Corrupt MDF File After RAID Failure
An MDF file recovered from a failed RAID can have the correct name and size while containing unreadable, missing, or incorrectly reconstructed database pages. The file should be protected before attach, repair, or extraction is attempted.
Keep the original members and the first recovered MDF, NDF, and LDF files unchanged. Do not use the only copies for repair, log rebuilding, or repeated attach attempts.
What this condition means
MDF corruption may originate inside SQL Server, in the filesystem, or in the RAID reconstruction beneath the file. A page-level error does not prove which layer introduced the damage.
If the RAID was rebuilt or recreated, the first task is to confirm that the file came from the most defensible storage state. Database repair performed on a wrong reconstruction can make a plausible but incomplete result harder to recognize.
What to record
- SQL Server version, database size, and exact attach or consistency errors
- Every MDF, NDF, LDF, backup, and recovered copy
- RAID level, controller, members, failures, and rebuild history
- Filesystem or file-recovery tools already used
- Priority tables, records, dates, and application functions required
What not to do
- Run repair with data loss on the only MDF
- Create a new log beside the only database copy
- Discard alternate recovered file versions
- Assume file size proves page completeness
- Write repaired output back to the failed array
How ADR evaluates it
ADR validates the storage reconstruction and preserves each database-file version before database analysis. Work proceeds only from copies.
The recovery plan is based on what remains consistent: the complete database when possible, or selected schemas, tables, rows, and priority records when full transactional recovery is not defensible.
ADR first validates which RAID reconstruction produced the file, then evaluates copies of the MDF, related data files, and transaction log. If a complete database is not defensible, recovery can focus on the tables and records the business needs most.
What happens next
A corrupt MDF can still contain valuable records. Recoverability depends on which pages remain readable and internally consistent, the condition of related files and logs, and whether a correct storage reconstruction is available.