“Our servers RAID array reported an error, so we called an engineer who attempted to do what he called remirroring, but it failed taking it down. He recommended DiskEng to us, who did an excellent job returning our data swiftly. Many thanks.”
Colin Henson, London
A pair of 2TB HGST hard drives, arrived from London at our laboratory in Oxford. Our hardware data recovery engineers examined the drives revealing both the drives to be in working condition. Sector-by-sector images of the drives were secured. During the imaging process both drives were found to contain a dozen unreadable bad sectors, which had resulted in the failure of the remirroring operation.
Each hard disk drive is manufactured with the ability to handle new bad sectors by swapping these with spare sectors, a list of each being maintained. This list is however, only a finite size which means over time it will become exhausted, after which any new bad sector encountered is returned to the operating system, or RAID controller. Any pair of hard disk drives which are operating under the same environmental conditions, also frequently purchased from the same supplier together, will normally deteriorate at a similar rate. This means once one drive starts to return bad sectors to the operating system, the other is likely to do the same soon afterwards.
The sector-by-sector images of the pair of drives were examined by our RAID recovery specialists, revealing that despite the prescence of bad sectors on both drives, the affected sectors were not the same. This allowed a full recovery of sectors, for which a virtual disk image was created. This virtual disk image was examined upon which a pair of NTFS partitions were located, one being an 800GB Windows Server boot volume, the other a 1.2TB data volume which was found to contain approximately 770GB of data files, all of which was successfully recovered and returned to the customer.