”An IT company set our RAID up and assured us it was using RAID 5, so we were confused when one disk failed overnight, it went offline and we were unable to attempt a rebuild. It soon became apparent through the RAID configuration tool that it was set up using RAID 0 and data recovery was our only option. Fortunately we keep regular backups, but it still contains very important data that would takes weeks to recreate. A big thank you for the hard work in recovering all the important files. Excellent service. Thoroughly recommended.”
Eric Wallesey, company withheld, Uxbridge.
Five 3TB NAS ready Western Digital hard disks arrived from Uxbridges at our laboratory in Oxford. The drives were inspected and all were found to be operating correctly, although one of the disks took a little longer to calibrate than the others.
Our hardware RAID data recovery engineers then secured sector-by-sector images copies of each drive. During the imaging process four of the drives imaged cleanly with no unreadable bad sectors encountered. While imaging the drive which had been slower to calibrate several areas on the drive were found to contain unreadable bad sectors. By undertaking a quick scan first, approximately 250,000 sectors were had not been secured. Through repeated scans of these areas our hardware specialists were able to reduce this number to approximately 100 unreadable bad sectors.
An examination of the disk images secured revealed that the RAID configuration was setup as level 0, where the data is striped across the disks with no parity data stored. Our RAID recovery specialists determined the configuration used and were able to create a virtual RAID array. The RAID was found to contain two NTFS volumes, 7TB and 8TB in size. All the bad sectors were found to have affected the first volume, causing considerable damage to system entries causing some files to be lost.
The first volume contained 2.4TB of recoverable data, while the second volume, which had suffered no damage contained 3.7TB of data. The most important data, some databases and scanned image data was located on the second volume. Despite the RAID failing while in operation, it was fortunate that it happened overnight, when the critical files were almost certainly not in use, so no damage was apparent. All the recovered data was written to a backup tape and returned to the customer.