Why data can be recovered

Electronic data recovery is through technology, will be stored in the disk drive, the notebook hard drive, desktop hard drive, storage server tape library, mobile hard disk, U disk, digital memory card, Mp3 and so on equipment lost electronic data to rescue and recovery technology.

In reality, many people do not know delete such as operating loss of hard drive formatted data can be restored, thought to delete, formatted data would not exist. In fact, the simple after operation data still exist in hard disk, know principle of data recovery knowledge only a few people will disappear under the data back, don't feel mysterious, understanding the data in the system, floppy disk, hard disk storage media such as principle, you can also personally do once the magician.

Data storage and restore the first step-partition

Hard disk storage of data for basic unit sector, we can understand for a book of a page. When we installed or buy a move hard disk, the first step is in order to facilitate the management-partition. No matter use what division tools, will be the first sector in hard disk label of hard disk partition quantity, each partition size, the information such as the starting position, the term say give priority to boot record (MBR), also somebody called division information form. When the master boot record for all sorts of reasons (hard disk bad way, the virus, the mistake, etc) are destroyed, some or all of the natural division would be lost gone, according to data information features, we can calculate again calculation partition size and position, the manual note division information table, "lost" partition is back.

Data storage and restore the second step-file allocation table

In order to management file storage, hard disk partition finished, the next job is formatted division. According to format programs partition size, reasonable division is divided into directory file will be assigned district and data area, as we see more novel, the pages for chapter directory, behind is the real content. File distribution within the table recording each file attributes, size, in the position of data. We all documents to the operation, all is according to the distribution of documents table. File distribution table after destruction, the system can't positioning to file, although each file content is still stored in the real data area, the system will still think file to do not exist already. Our data lost, like a novel directory was torn off. Want to go directly to the chapter, is no longer possible, to get to the content (recover the data), only in the content of memory know about pages, or each page (sector) looking for you to content. Our data can also be back.

Data storage and restore the third step-formatting and delete

We store files in to the hard drive, the system will first in the documents written within the distribution list file name, size, and the free space, according to data in file distribution list the contents of the documents written in data to continue the starting position. Then began to write the file data area real content, a file storage operation just calculate finished.

Delete operation but simple is, when we need to delete a file, the file system is only in the inner the file distribution table write in front a delete sign, said the document has already been deleted, he the space that takes up has been "release", other files can use his take of space. So, when we deleting files and want to find him (data recovery), just use the tool will delete sign take out, data is restored back. Of course, the premise is not new to file, the file the space that takes up new content is not covered.

Formatting operation and delete similar, only operating file distribution list, but format is put all the files and delete sign, or simply will file distribution table to empty, the system will think hard disk partition does not exist any content. Formatting operations have not to do any operation data area, the directory is empty, the content is still in, with the aid of data recovery knowledge and the corresponding tools, data can still be restored back.

Data storage and recovery step 4--understanding covered

Data recovery engineer is often said: "as long as they do not cover data, data may be back".

Because disk storage properties, when we don't need the hard disk data, data and not be taken away. Deleted in the document system just write a delete marks, format and junior format is also in the disk to write a times covered in digital 0 for content of data, this is covered.

A file was marked deleted after mark, he occupies the space in a new document writing, will likely be the new file take cover new content write. Then delete the file name are still there but he pointed to the data space has been covering the content change, restore out will be error exception content. The same file distribution table the file information there were deleted mark the space that takes up but also may be new filename file information take cover, the file name will not exist.

When a partition format, copy the new content, new data is only cover off before the division of space, remove the new content of take up space, this division the remaining space data area on the content is still possible disorder to be organization, data recovery will come out.

Similarly, cloning, a key recovery, and make the system restore data loss, as long as the new data take up the space is less than before destroying spatial capacity, data recovery engineers were could restore you to partition and data.

Data storage and recovery step 5-hardware failure data recovery

Hardware failure accounted for more than half of all data accidental failures, often by lightning, high pressure and high temperature, the circuit faults caused, high temperature, vibration caused by collision of mechanical failure, high temperature, vibration collision, storage medium caused by aging of physical bad track sector fault, and, of course, the accidental loss damage of the firmware BIOS information, etc.

Hardware failure data recovery of course is first diagnosis, suit the remedy to the case, to repair the corresponding hardware failure, and then according to repair other soft fault, and will eventually recover data success.

Circuit fault need we have circuit basis, need more in-depth understanding of hard disk detailed work principle process. Mechanical fault need to head the table or above level 100 workshop for diagnostics repair work. And there should be some software and hardware maintenance tools with to repair the firmware area fault type.

Data storage and recovery step 6-disk array RAID data recovery

Disk array of storage principle here don't make its interpretation, can see this site array knowledge article, the restoration process is to exclude hardware and software fault, and then analyzes the array of order, size parameters, with array card or array software reorganization, restructuring and recover the data using conventional methods.