Data recovery is a procedure of recovering the lost data in the computer. When your computer had problem with storage device it happened. This is the easiest way to find the damaged files.
LOGICAL DAMAGE
Logical damage caused to the file system by power outages. Power outages protect the file system while written and stored but if the problems are with drives and hardware they have the same result. Due to this the file system remains in conflicting condition and can cause different problems such as considerably recursing directories, negative amount of free storage. In logical damage your system can crash and even the actual data can be lost. There are many data recovery software which can correct these inconsistencies and now new operating systems are coming with the repairing tools. For example fsck utility is available in Linux and chkdsk is used in Microsoft Window. Data can be recovered from third party utilities also.
There are two techniques used for repairing programs. The first one is checking of consistency. This technique is used for scanning the structure of the disk and to check the consistency with specifications. For example a directory has two entries 1) a dot (.) – Itself entry and other dot-dot (..) – Entry to parent. On repairing the system will reach to each directory and repair the same. If there is an error message then it can be printed to correct the problem. Both techniques of repairing the system are in the fashion. But if the system is too much damaged then it can be completely failed during consistency check. In this case it may not be recognizing the drive with valid file system.
Second technique for repairing the file system is using hints for recovery. It either can recover the data or can rebuild the file system from scrape looking with achievable margins. . A third – party technique can also be used for recovering the file system. This program works slowly than consistency checking. The technique does not repair the fundamentals of file system but just allow extracting data form it to other storage device.
These two techniques are used for repair of logical damage and data recovery, but software can not give the guarantee that no loss of data will occur.
The use of NTFS 5.0, ext3, and xfs file systems has decreased the occurrence of logical damage. With this system the files ROLLED BACH to the consistent state. Regular maintenance of the system can give help to consistency checker if the file system failed.
PHYSICAL DAMAGE
There are many reasons for physical damage to the storage media. Any of these reasons can damage the data like i) Scratch on the metallic surface of CD-ROM ii) Scratch on the dye layer iii) mechanical failure of hard disk i.e. failed motors / head crashes iv) breaking of tapes. When physical damage takes place, files of the system get damaged also. First of all deal with the logical damage then recover the lost files.
Physical damage to computers can not be repaired by the users. This is a hard disk work and the person who knows the hardware of the computer can only perform this action. The experienced hardware person can recover all the lost data with his technical expertise. For major problems data recovery companies can be consulted. These companies use cleanroom facilities of Class 100 to save the data during repairs.
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