This case study documents the successful emergency restoration of an Interbase 7.5 database that was rendered inaccessible due to hardware-level disk degradation. By performing low-level binary surgery on corrupted pages, the AS Data Recovery team achieved a 100% recovery rate.
Client & Data Information
- Client Name: Confidential
- Data Type: Interbase 7.5 (.GDB / .IB)
- Data Capacity: 1 GB
- Primary Issue: Physical Bad Sectors / File Truncation /
Internal GDS software consistency check
Incident Summary
The client’s server experienced a hardware failure on the storage partition, leading to the development of bad sectors. Because Interbase uses a highly structured page-based architecture, even a single unreadable sector in a critical area (like the Header Page or Pointer Pages) can trigger a fatal GDS (Gateway Data Software) consistency check.
The client attempted to run standard repair utilities, but the software reported “End of file reached” or “File truncated.” This occurred because the file system could not read the data trailing the bad sectors, making the 1 GB database appear smaller or incomplete to the Interbase engine.
Technical Analysis
Upon forensic analysis of the Interbase environment, AS Data Recovery engineers identified:
- Page Header Corruption: The specific sectors containing the database’s “Page Map” were physically unreadable.
- I/O Range Errors: The error “reached the end of its range” indicated that the database’s internal metadata expected more data pages than the operating system could currently provide due to the bad blocks.
- Logical Integrity: Despite the physical blockage, a bit-level scan of the healthy sectors confirmed that the actual table data (the row segments) remained intact and consistent.
Recovery Solution
The recovery strategy utilized Physical Block Remapping and Binary Header Repair. Since the Interbase service could not mount the database, our engineers bypassed the database engine entirely. Using proprietary forensic imaging tools, we performed multiple “gentle” reads of the bad sectors to stabilize the data. We then manually repaired the database header to match the actual physical page count, allowing the internal GDS checks to pass.
Recovery Process
- Forensic Imaging & Stabilization: Used hardware-based imagers to create a bit-perfect clone of the 1 GB file, effectively “working around” the bad sectors to capture every available byte of data.
- Manual Binary Repair: Manually corrected the corrupted pointers in the database header and recalculated the checksums for the damaged pages.
- Consistency Check Bypass: Adjusted the internal flags that were triggering the
internal GDS software consistency check, enabling the database to be opened in a “Read-Only” forensic mode. - Logical Extraction: Performed a full metadata and data dump (Transportable Backup) of the repaired file.
- New Database Restoration: Restored the backup into a fresh Interbase 7.5 environment, ensuring that all indexes and constraints were rebuilt on a healthy disk.
Recovery Results
- Recovery Integrity: 100% (Zero record loss)
- Recovered Volume: 1 GB
- System Status: Database fully operational on new hardware.
- Customer Satisfaction: Extremely Satisfied.
Expert Reminder from AS Data Recovery: When Interbase throws a “GDS consistency check” error, the engine is trying to protect the data from further corruption. Do not use gfix -mend repeatedly on a disk with bad sectors, as the write operations can permanently destroy the very data you are trying to recover. Contact AS Data Recovery professionals immediately for hardware-level forensic extraction.