Case Study: Recovery from a Critically Failed RAID 0 Array Following Controller Re-initialization
Client Profile: User of a two-drive RAID 0 (striping) array.
Presenting Issue: Complete data loss after disconnecting the RAID 0 drives to install an SSD. Both drives are now reported as “uninitialized” in the system BIOS and are invisible to the Windows operating system, suggesting they are blank.
The Fault Analysis
The client’s actions inadvertently triggered a catastrophic failure specific to hardware-based RAID arrays. The core issue is that the RAID configuration is not stored within the Windows OS but in the RAID controller’s firmware NVRAM and, critically, in a small, reserved area on the physical drives themselves known as the RAID Metadata.
When the client disconnected the drives from their original controller and booted from a new SSD, one of two events occurred:
Controller Re-initialization: Upon reconnection, the RAID controller failed to recognize the existing RAID structure and interpreted the drives as new, unconfigured members. It may have then overwritten the critical RAID metadata on both drives with a new, blank configuration, effectively “uninitializing” them.
Metadata Corruption/Loss: The act of hot-plugging or reconnecting the drives to a different SATA port (or the same controller in a different state) caused the controller to lose synchronization with the metadata, corrupting it.
A RAID 0 array stripes data without parity, meaning file blocks are split evenly and sequentially across both drives. The loss of the metadata is catastrophic because it contains the essential parameters needed to reassemble the array:
Drive Order: Which physical drive is the first member of the stripe.
Stripe Size: The block size (e.g., 64KB, 128KB) written to each drive before switching to the next.
Data Offset: The sector where the actual user data begins on each drive, after the metadata region.
Without this “map,” the BIOS and OS see two individual, unformatted drives. The data is almost always physically intact on the platters, but the system lacks the instructions to piece it together.
The Bracknell Data Recovery Solution
This recovery required a deep, forensic-level approach to manually reconstruct the lost RAID parameters and virtually reassemble the array.
Phase 1: Physical Drive Imaging and Metadata Region Analysis
Each drive was connected to our PC-3000 system and DeepSpar Disk Imager to create sector-by-sector forensic images. This isolated the drives from the unstable host system.
Sector 0 Interrogation: We first examined the first few sectors of each drive image for any remnants of the original RAID metadata. In many cases of re-initialization, the old metadata is not securely erased but simply unlinked. Our tools successfully located overwritten but recoverable fragments of the original metadata signature.
Manufacturer Signature Scan: We scanned the drives for known vendor-specific metadata signatures (e.g., Intel, LSI, AMD). While the primary metadata was corrupted, we identified ancillary data structures that confirmed the drives were part of a RAID 0 set and provided clues to the stripe size.
Phase 2: Empirical RAID Parameter Reconstruction
With the metadata lost, we employed empirical data analysis to reverse-engineer the array’s configuration.
Stripe Size and Order Determination: Using our proprietary software, we performed a block-based analysis across both drive images. The software tested millions of potential stripe size and drive order combinations, looking for a configuration that created a coherent, unified data stream.
File System Signature Validation: The key validator was the NTFS Boot Sector. When the software tested the correct combination of drive order and stripe size, the very first logical sector of the virtual RAID 0 volume displayed a perfect NTFS signature (
EB 52 90 4E 54 46 53). This confirmed we had successfully located the start of the logical volume.Data Block Correlation: We further verified the configuration by checking that file system structures like the Master File Table (MFT) were reassembled without gaps or misalignments. In a correctly configured RAID 0, the MFT entries will span both drives in a predictable, alternating pattern.
Phase 3: Virtual Array Assembly and Data Extraction
Once the precise parameters (Drive Order: 0-1, Stripe Size: 128KB) were empirically proven, we built a virtual RAID 0 within our recovery software.
Linear Image Creation: The software combined the two drive images into a single, linear virtual disk file, interleaving the data from each drive according to the deduced 128KB stripe size.
File System Mounting and MFT Parsing: This virtual disk was mounted. The NTFS file system was found to be entirely intact. We parsed the $MFT to rebuild the complete directory tree and file metadata.
Integrity Checks: We performed checksum verification on recovered files, confirming that the striping algorithm was correctly applied and that data was extracted without logical corruption.
Conclusion
The client’s data was not “erased” but had become inaccessible due to the loss of the critical RAID metadata that acts as a key for the striped array. Standard system tools are incapable of solving this problem as they rely on the controller to present a pre-assembled logical drive. Our success was achieved by forensically imaging the drives and using advanced software to manually determine the original RAID 0 configuration through empirical data analysis, effectively recreating the lost “key” and reassembling the data.
The recovery was completed with 100% success, returning all data from the point-in-time of the array failure with full directory structure and file integrity.
Bracknell Data Recovery – 25 Years of Technical Excellence
When your RAID array fails due to controller error or metadata loss, trust the UK’s No.1 HDD and SSD recovery specialists. We possess the specialised hardware and software to manually reconstruct failed arrays and recover what operating systems and BIOSes declare lost.