Data loss can occur owing to any number of causes. For example: intentional or accidental deletion of a file, through misplacing of concerned CDs or other storage media or even due to administrative errors. However, what is of importance in the given context is the loss of data owing to hardware and software / logical causes. There can be several hardware and software / logical causes that may lead to loss of data.



Hardware Causes

In case of hardware, one might have a hard disk drive crash or as it is more commonly known a head crash. This is a very specific kind of hard disk drive failure. A head crash occurs when the magnetic media on the surface of the rotating platters comes in contact with the read / write head of the given hard disk drive.

Considering the fact that the platters move at exorbitantly high speeds, a head crash can cause truly extensive damage to the system. All the more as in such an eventuality the particulate that have been resulted owing to the crash can cause further damage to the system of the hard disk drive.

The head moves across on a thin film of air. This film of air is itself moving and it is entrapped at platter surface. First of all, there is a very thin lubricant layer at the topmost level of the patter. This is followed by another layer which is of sputtered carbon. Both of them combined protect the magnetic layer of the platters from any accidental touch by the head.

However, even a tiny particle of dust can cause the read / write head to bounce, instead of the smooth movement, against the platters. The read / write head of the hard disk drives is made up of materials that are hard enough to scratch the surface of the platters, which are very delicate. Such a bouncing of the read / write head against the platters can destroy their thin magnetic coating.

Software / Logical Causes

There can be numerous problems with the software which can cause a loss of data. If data loss occurs owing to software causes, then it is said that the loss is owing to logical causes. One such cause can be what is referred to as a software freeze.

Software Freeze: This happens when a programme does not function properly and stops responding to commands from other parts of the given operating system. In other words, it seems to simply freeze. If such a freeze occurs in a part that is of vital importance to the operating system, then the entire system may crash.

• The crashes can be owing to what is referred to as instructions from a single machine. This, however, can be a misleading statement as the reasons behind it may be manifold. For example, if what is called a program counter is set to an address which is not correct or somehow the program code gets overwritten owing to some previous problem.



• Another cause of a logical crash can be what is called a race condition. In this scenario, a signal is sent by one process to another. If the other process is already busy, then it is but obvious that the signal will have to wait. In a bizarre scenario, it may be that the two processes are sending signals to each other. In this case, the signals from both sides will have to wait endlessly. If one of the processes is of critical importance to the system, then the system may crash.

Irrespective of what has caused the computer system to crash, its implications can be seriously harmful for the computer user. One has to take all possible steps in order to avoid loss of data owing to hardware or software crashes. Unfortunately, there is little that can be done in this regard.

One can try to avoid unnecessary / possible damage to the hard disk drive by seeing to it that the hard disk drive is not subjected to avoidable shocks and vibrations.