There are many free or cheap data recovery tools available on the internet, which are tempting to use in the event of a failure, due to the potential for saving money. There is however, a risk especially if your hard disk drive is suffering a physical failure, as the problem will only get worse.
It is for this reason that at DiskEng we secure an image of your drive first, to ensure that we have harvest the maximum amount number of sectors, which is extremely important on a failing drive. We prefer that the drive is sent for data recovery without any attempts being made at recovering the data yourself, as the problem may have been made worse.
Taking a Risk is a Gamble
Accessing the disk directly to fix the problem or recover the files can be a bit like playing Russian Roulette, especially if the hard drive is starting to fail, or there is severe corruption of the file system metadata structures. While many people have had success using such utilities, we have seen many examples where further damage has occurred to the drive or important data structures have been deleted overwritten with incorrect information.
If it works, the gamble has paid off, but when it doesn’t, the data recovery process may be considerably more complex than it would have been and can result in data loss. In the worst cases we have seen, the file system data structures been completely destroyed, leaving a data trawl the only available option, which can only recover some files, which will not have their original file names.
Dealing with Errors
It is important to understand that if your data has become inaccessible, it means that an error has occurred, whether it’s physical damage or logical data corruption. The reputation of any data recovery software depends on well it is able to cope with errors and if an unreadable is encountered, how it deals with that.
Repeatedly attempting to read an unrecoverable bad sector can lead to further damage occurring to the surface of the hard disk, which if it happens can very quickly destroy large areas of the disk surface. Any process which attempts to alter the contents of a hard disk drive is a serious risk, as a mistake could severely decrease the chances of recovering the files stored on the drive.
Impact on Data Recovery
When a hard disk drive arrives at our laboratory, with the information that attempts have already been made to recover the data, our data recovery specialists tend to suffer a sinking feeling. In order to avoid any further damage once the physical state of the drive has been assessed and remedial work untaken, a sector-by-sector image of the drive is secured.
All further work is undertaken using the image of the drive, with any modifications required, stored separately to ensure data integrity. Unfortunately, we cannot predict how successful the data recovery from a hard disk where previous attempts to recover the data will be. These can range from recovering all the files intact through serious data loss to a total catastrophic failure, such as a head crash resulting from repeated attempts to read unrecoverable sectors.