MySQL Data Recovery
Direct answer
MySQL fails from corrupted InnoDB tablespace (ibdata1, .ibd), crashed MyISAM (.MYI/.MYD), lost binary log, bad updates and crashes during write. HD Doctor recovers 90% of MySQL cases via InnoDB recovery, MyISAM repair and native tablespace parser. With 24+ years and 320+ MySQL/MariaDB cases.
Critical: do NOT run innodb_force_recovery > 4 without backup, do NOT delete ibdata1 thinking it's just log, do NOT run REPAIR TABLE on MyISAM with I/O errors.
How MySQL organizes data
MySQL/MariaDB uses storage engines: InnoDB (default, transactional, ACID with .ibd per table + ibdata1 system tablespace + ib_logfile redo log) and MyISAM (legacy, with .MYD data + .MYI index + .frm schema). Common failures: InnoDB page corruption, ibdata1 destroyed after disk full, MyISAM table marked as crashed, lost binary log and crashes during COMMIT.
Common MySQL symptoms
- InnoDB: "Table doesn't exist" but .ibd exists in filesystem
- InnoDB: "Tablespace has been discarded"
- MyISAM: "Table is marked as crashed"
- Error 1932 (table not found in engine)
- MySQL won't start, ibdata1 corrupted
- Binary log corrupted or missing
- Replication broken, slave not in sync
- Database in SUSPECT after OS crash
Most frequent MySQL causes
| Cause | % | Recoverable? |
|---|---|---|
| Corrupted InnoDB tablespace (.ibd or ibdata) | 32% | ✅ Yes, InnoDB parser |
| MyISAM crashed (table is marked as crashed) | 20% | ✅ Yes, MyISAM repair |
| Storage failure under datadir | 15% | ✅ Yes, storage recovery first |
| Crash during COMMIT (inconsistent data) | 12% | ✅ Yes, redo log + recovery |
| Accidental DROP TABLE/DATABASE | 10% | ✅ Yes, file carving |
| Lost binary log (replication) | 6% | ✅ Yes, slave-based rebuild |
| Other (post-update corruption) | 5% | ✅ Yes |
Source: HD Doctor internal stats on 320 MySQL/MariaDB cases between 2022 and 2025.
What NOT to do with a failing MySQL
- 1.Do not run innodb_force_recovery > 4 without backup. Mode 5+ can destroy indexes and still-recoverable data.
- 2.Do not delete ibdata1. ibdata1 contains system tablespace, undo logs and (in legacy config) table data.
- 3.Do not run REPAIR TABLE with I/O error in progress. Can amplify MyISAM table corruption.
- 4.Do not copy .ibd between databases without matching ibdata. Tablespace IDs need to match data dictionary.
- 5.Do not run mysql_upgrade with database in SUSPECT. Schema update on corrupted database can brick instances.
- 6.Do not run FLUSH TABLES with issue in progress. Can force write of pages in inconsistent state.
How HD Doctor recovers MySQL
We work on datadir copies. For InnoDB we use native parser; for MyISAM, header and index reconstruction.
- 1
datadir intake
You send the entire datadir/ or MySQL server drives.
- 2
Diagnosis within 24h
MySQL version, engines in use, corruption type identification.
- 3
Free written quote with scope
Technical analysis before approval, listing viable tables.
- 4
InnoDB recovery
For InnoDB, native parser extracts pages from .ibd, ignores corrupted and rebuilds data dictionary if needed.
- 5
Technical MyISAM repair
For MyISAM, we rebuild .MYI from .MYD and validate via myisamchk.
- 6
Recovery via redo log
When ib_logfile is available, we apply controlled redo to reach last consistent COMMIT.
- 7
Extraction via custom parser
For extreme cases, we extract individual rows from InnoDB filesystem ignoring corrupted indexes.
- 8
Data validation
We compare row counts and integrity in test instance.
- 9
Delivery + final report
Restored database or SQL/CSV dump, signed engineer report.
Turnaround and SLA
| Scenario | Turnaround |
|---|---|
| MyISAM crashed (1 table) | 3–7 business days |
| Corrupted InnoDB tablespace | 5–12 business days |
| Complete database + storage failure | 10–20 business days |
| Accidental DROP + file carving | 8–15 business days |
- 24h emergency SLA available for production MySQL.
- No Data, No Charge policy: if we can't recover the critical tables you flagged, you don't pay for the service. Diagnosis is free in 92% of cases.
Versions and environments supported
We service MySQL 5.5, 5.6, 5.7, 8.0, 8.1, 8.2, 8.3, 8.4. MariaDB 10.x, 11.x. Percona Server 5.7, 8.0. Engines: InnoDB, MyISAM, Aria, MEMORY, ARCHIVE, CSV. Configurations: standalone, master-slave replication, Group Replication, MariaDB Galera Cluster. AWS RDS MySQL/MariaDB with snapshots.
Why HD Doctor for MySQL
- 🏛️24+ years focused exclusively on data recovery
- 🔬Class 100 cleanroom + in-house MySQL infrastructure
- 🧠Native InnoDB parser + MyISAM repair + redo log recovery
- ⚡24h emergency SLA for production MySQL
- 🤝Only Western Digital Platinum Partner with a regional lab
- ⚖️Signed engineer report valid for forensics and insurance
MySQL FAQ
InnoDB "Tablespace has been discarded". Recoverable?
Yes, in 88% of cases. Means .ibd and ibdata are divergent. We reattach via parser and extract data.
MyISAM "Table marked as crashed". Any chance?
Yes, in 95% of cases. MyISAM crash is usually repairable via .MYI rebuild from .MYD.
Accidental DROP TABLE yesterday. Recoverable?
Yes, in 80% of cases if disk wasn't heavily written. In InnoDB with file_per_table, .ibd usually persists until overwrite.
Replication slave broken. Can you recover?
Yes. We rebuild via available binary log analysis or re-sync from master.
How does the quote work?
Diagnosis is free. After technical assessment within 24h we send a detailed quote.
Do you serve AWS RDS MySQL?
For RDS, we recover via available snapshots or database export. Catastrophic failures need direct AWS support.