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Almost all SME, (Small to Medium Enterprises), have turned to RAID-configured storage on their servers in recent years for their mission-critical applications and data. In spite of being considered highly fault-tolerant, RAID does fail. RAID can fail due to component failure (including hard drives and controller cards), operating and application corruption, but most commonly, simple user error, often leaving the data unusable and corrupted.
RAID's are amongst the most complex media devices to recover data from. The data configurations are quite complex such as striped, volume, spanned etc. Sadly, different manufacturers will often use bespoke configuration applications that can add further complexity.
While state-of-the-art recovery tools and techniques are essential, ultimately it is the experience of both the recovery engineers and the software coders that makes the difference between a successful recovery and a failure. Successful RAID recovery often depends on an extremely fine-tuned sense of pattern recognition that is developed over years and years of recovering data from complex RAID configurations.
Disklabs Data Recovery and Computer Forensic Services is part of the 1 st Computer Traders Ltd group, which encompasses a company that repairs and sells hard disk drives, a company that specialises in surplus and end of line computer equipment, and of course a Data Recovery and Computer Forensics Services company.
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Each
bit of data word is written to a data disk drive (4 in this example: 0 to 3).
Each data word has its Hamming Code ECC word recorded on the ECC disks. On
Read, the ECC code verifies correct data or corrects single disk errors.
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 Advantages
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 Disadvantages
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'On
the fly' data error correction
Extremely high data transfer rates possible
The higher the data transfer rate required, the better the ratio of data
disks to ECC disks
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Very
high ratio of ECC disks to data disks with smaller word sizes - inefficient
Entry level cost very high - requires very high transfer rate requirement to
justify.
No commercial implementations exist.
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Thanks to AC&NC for their technical input into this page.
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