“When our server failed an on-site engineer could not fix it, and recommended DiskEng to us. We have been thoroughly impressed with the professional and friendly service. Many thanks for recovering some critical data, allowing us to meet a tight deadline.”
Patrick Connor, ROS Control Systems, Heathrow London
A server system containing a pair of 2TB Western Digital drives, configured as a RAID 1 mirror, arrived from Heathrow at our laboratory in Oxford. An examination of the drives revealed that both the drives were in working condition, but contained a number of bad sectors, which had resulted in a failure to resynchronise the data correctly to a new drive.
All hard disk drives are manufactured with an inbuilt ability to deal with bad sectors by swapping these out for spares, for which a list is maintained. However, this list is a finite size, so that over time it will filled up, leading to bad sectors being returned to the operating system, or RAID controller. Any set of hard disk drive operating within the same environment, often purchased together from the same supplier, it is normal for the defect lists to grow at a similar rate.
Sector-by-sector image copies of the two drives were examined by our RAID recovery specialists, which revealed that despite the bad sectors on both drives, they affected different sectors, allowing a complete virtual disk image to be created. An analysis of this virtual disk image found two NTFS partitions, the first a 500GB Windows Server installation, the second a 1.5TB data volume containing 830GB of data files.