When we discuss of hard disc data recovery, we primarily focus on issues surrounding hard drive failures; since failures are usually the common cause. There are really two primary forms of failure in a hard drive, logical and physical. Logical failures are usually a result of file-system corruption. This can occur due to a virus, accidental deletion of key files or registry components, and in some cases even electro-static discharge. In most cases where a logical failure has occurred, the drive is still recognized by the system BIOS, but it will not boot. In most cases, your data should still be intact on the drive, even though it may appear to be inaccessible.
If the system BIOS does not detect the presence of the hard drive, then chances are a physical failure has occurred. Physical failures can result from a wide variety of causes. There are really two sub-categories for physical hard drive failures; mechanical and electronic. Mechanical failures usually result from a failure of the spindle motor. Spindle motor failure can result from excessive heat due to a bearing failure. The increased heat resulting from the bearing failure will expand the drive shaft and therefore seize the spindle motor. Suddenly, your drive will become inoperative.
Another physical issue that sometimes rears its ugly head is an electronic failure. If you look at a hard drive you will notice a circuit board on the bottom. This board is basically the brains of the drive, and it is where the computer interfaces to the hard drive. An electrical failure can occur unexpectedly at any time. Even brand new hard drives are not totally immune to having electrical failures. Sometimes it’s just a faulty component; sometimes it’s improper installation (i.e. electro-static discharge, grounding out the board, damaging circuitry during installation).
How is HD Data Recovered
One of the most often asked questions that customers ask is, “how do you get my data back?” Well, it’s really not black magic or rocket science. It’s just a matter of having the right tools and the knowledge necessary to know what to do, much like a surgeon performing heart by-pass surgery. Many prominent data recovery facilities have a large array of hardware, software and tools for recovering data.
Generally speaking when a hard drive is received by a data recovery firm, the first thing they do is evaluate it, and determine what recovery solution will be necessary. If the drive failure is a logical issue as mentioned earlier, then a scan of the drive will be performed to try and repair the file system corruption. Sometimes a partition can be repaired and the drive restored to the status that it was before the failure. If this is not possible, then a very low-level scan will be performed that essentially searches every sector of the hard drive for files. Once the files are located, they can then be copied to the media of choice, i.e. a CD-ROM, DVD-ROM or another hard drive. Logical recoveries can take up an enormous amount of time, especially if the drive is on the verge of physical failure. It’s not uncommon to allow for one day of scanning and a day for recovering the found files.
If the drive has suffered a physical failure, then the recovery procedure is quite a bit more challenging. As mentioned above, there are really two sub-categories of physical failure; mechanical and electronic. An important element in recovering data from a physical failure is having the necessary parts to get the drive functioning again. In cases where the electronic circuit board has failed on the hard drive, then you have to have the exact same circuit board on hand in order to retrieve the necessary circuit components for replacement. Anytime a hard drive is having an invasive procedure performed on it, a lab or room with very minimal air impurity is used.