FALLEN HARD DRIVES
It is a common thing for a palm sized multi TB hard disk to experience a fall in its life time. Such hard drives by all the companies such as WD,Seagate,Toshiba,Fujitsu etc are all very sensitive to shock. Infact, some of the drives will have mentioned the maximum amount of shock they can take. Here we are strictly talking about mechanical shock/jerk. When a drive experiences such a misfortune, it is possible that the internal head alignment is lost and it stops getting detected. Most of the hard drives have their service area written on head number 0 and 1. If your luck is really good and one of the two heads among 0 or 1 (or both) are still in alignment and working after reciving a shock, it is possible for us to have that drive detected and selectively recover data from just the working heads while disabling the mis-aligned heads. It is also possible that the drive may suffer head and platter sticktion which I will try to cover in the next blog.
Most of such hard drives have multiple heads in a single stack. Our tool DeepSpar enables us to disable the heads which are faulty and gives data at enormous speed from the working heads.
If there are four heads in a stack and only three work, then the loss is 1/4th ie 0.25% Similarly if there are eight heads and only five are giving data then the loss is 3/8th which is around 37.5% In such cases, lengthy files of any type ie multimedia or database may suffer damage. Such files only open up if the file integrity is intact.
What May Work?
Small files such as .doc files taking less space have a greater chance to work. All the data which is written fully or partially under the faulty heads shall not work