More about Data Recovery

Data recovery is not a simple technology, though in some cases data is recoverable with simple recovery softwares. But quite often it's very difficult and challenging, and demands extraordinary engineering skills. Here we share some of different kind of problems usually we encounter.
Based on the complexity, broadly we can categorize the data recovery problems into two types, Logical and Physical. Logical problems are usually simple in nature and require relatively lesser effort than physical problems hence attracts less charges, whereas physical problems require great engineering skill and effort. Obviously, recovery solutions to physical problems attract more charges in the industry. Let us discuss some general causes/symptoms of both kinds of problems. The discussion is for basic illustrative purpose only as exhaustive list and explanation never be complete in data recovery technology.

Logical problems
In this case Hard disk will be detected in CMOS setup and does not have bad sectors in it. These problems may likely be due to In most of the cases the entire data can be recovered quickly using advanced methods and technology. An example of this kind illustrated below.

Suppose a 500GB hdd having 3 partitions namely C =50GB, D=200GB and E=215GB. Windows installed in C drive and important data present in D and E drives. If all the partitions are deleted and freshly 4 partitions are created with C = 50GB, D = 100GB, E = 150GB, and F =165GB with Operating System installed in C drive and NO data copied in other drives ( D,E,F) then entire data can be recovered from earlier D and E partitions.But if data is re-written on the same partition then complete data may not be recoverable.

Physical problems
There are various kinds of physical problems. Some of them are
  1. Hard disk with bad sectors
  2. In this case hard disk is detected in CMOS (BIOS) setup but data can't be copied from the disk. Usual symptoms of this type are:
    • Hard disk detected in CMOS (BIOS) setup but not visible in disk management
    • Hard disk detected in CMOS (BIOS) setup and takes long time to appear in disk management.
    • If this hdd is connected to a system, it makes the system to hang/unresponsive.
    • System hangs when you run recovery softwares on it.
    • Sometimes unusual/abnormal sounds come from hdds.
    • SMART fail / hard disk fail message appears when system switched on.
    If the affected hdd has bad sectors then you must be very cautious, because in this case data recovery is often complicated. It is advised not to take any chance and better to approach qualified professional people. They can tell the existing folders within an hour in most of the cases. Bad sectored hdd is very sensitive and bad sectors spread quickly which leads to further damage to the data. Also this hdd should not be scanned with recovery software.
  3. Undetected Hard disk even in CMOS
  4. This is usually a typical case of dead disk. Hard disk may become dead due to various reasons.
    • Burnt circuit board
    • Problems in media
  5. Hard disk undetected in CMOS and abnormal sounds come from hdd.
Any issues or combination of the issues mentioned could cause data loss. And based on the complexity of the data recovery the affected media is placed into one of the five levels devised by Vigna.