Every computer user would encounter problems with their system at some time or the other. Most often, their hard drive would be proper and not malfunctioning. Still, they find that data is lost. This could be due to user activity error, virus, power outage, system boot error and failure of the created backup media. Recovering of data lost thus, is logical data recovery.
Logical damage to the computer often occurs as a result of power outage. Due to a sudden power failure, the file system structure cannot be fully written to the storage medium. Data stored on the media is consequently left in an inconsistent state. Inconsistent data leads to data loss, corruption of the files and instability of the operating system.
Logical Data Recovery
Business establishments seek professional expertise for logical data recovery. Software professionals use various programs to repair inconsistencies in the file system and recover data. All the programs make use of either of the two main techniques for logical data recovery.
Windows OS and Linux provide software utilities for repairing file systems that have been logically damaged.
- The logical structure of the disk is scanned and checked to ascertain that it conforms to its logical specifications.
- The directory should have two entries in any file system. A single dot entry is where the file points to itself and a double dot entry that point to its parent.
- A repair program checks each directory and ascertains that the entries exist as per the specifications and point to the right directories.
- And, if they do not conform to specifications, an error message is printed and the problem rectified.
But the problem with this program is that if a file exists out of place, it gets immediately deleted.
- The entire hard drive is scanned.
- The existing file system structure and the possible boundaries are made note of.
- Then an attempt is made to rebuild the entire file.
Logical data recovery is possible by either of these two methods. But data loss is possible when two files wrongly share the same allocation unit in the FAT file system. The journaling file system that is increasingly being used helps prevent data loss due to logical damage.
About 70% of the computer-related problems resulting in data loss are a result of logical failure rather than physical disk problems. Physical damages occur when the computer is broken, has fallen down from a height, has been submerged under water, or short-circuited. When such physical damages occur to the computer the Basic Input Output System (BIOS) may not be able to recognise it.
The computer user should first identify what the actual problem is. This would help in saving a lot of money while attempting data recovery. Recovering data that has been lost due to a logical failure is not very expensive.
Data recovery costs less when the data is recovered by companies that specialise only in logical data recovery. These companies do not require the sophisticated clean room facilities for their operations. The construction and maintenance of such rooms (Class 100 or Class 10) is very expensive; and companies pass on these expenses to their clients.
Data loss can never be completely ruled out. However, this loss can be reduced to the greatest possible extent by creating a backup. Using a UPS to provide continuous power supply till the computer is properly shut down offers protection against power outages. Using Redundant Array of Independent Disks (RAID) can prevent data loss to a great extent.
Majority of the data is lost due to logical failure. Computer users should take steps to safeguard data. In spite of the precautionary moves, data loss might occur. If data recovery is still not possible, professional expertise can be sought.