Symptom:
Sometimes, the file recovered with Data Trace Recovery is incomplete, such as
File name is missing
Only part of file content is viewable or cannot be open at all
File recovered in 0KB while product can list it in original size first
This article will try to explain why this happens and provide you possible solutions if you are experiencing one of the situation now.
Background:
To know why the issue happens, it is required to understand how a file is stored on a hard drive first. Usually, a hard drive must be formatted two times separately with low level format and Windows format before you can write a file onto it.
Low level format is naturally done by hard drive manufacturer, it will divide each platter
into multiple concentric circles named Tracks first, and then create many (usually 63) area
on each track for saving data, the area is called Sector (The size of a single sector is usually 512 bytes or 4KB).
Data is still unable to write to the drive although the ‘room’ for data is prepared. As there is no directory info to manage how the written data should be saved. We all know Windows format will create a partition on unallocated space, and the required ‘directory info’ is also created during this operation. After the ‘directory info (file system)’ created, new
written data will be organized with specific rule in the partition. File name, time stamp, size info and some other file properties are saved to directory part (file table), while file content is separately written to data storage part. And sometimes, a file may not be saved in continuous sectors, that’s why defragment is necessary to improve partition I/O speed. A hard drive used for a period of time maybe look like the picture below shows.
Cause:
Only when the two parts, Directory info and content in storage area keep completely untouched, data recovery tool can help you recover data in exactly original status. If either of the info is damaged because of new written data after data lose, further operation on the partition or hardware issue, you will get the error mentioned at the beginning of the article.
And a huge file, such as Bluray video file more than 20GB, might be divided into thousands of pieces in a partition, it is also hard to recover all of them correctly.
Solution:
There are two ways in our product to detect file during a scan. The main one is based on file directory info, the scan process will try to rebuild files with all file properties read from the
directory part of a partition. In this way, recovered files will be listed in original file structure and with original file name and file attributes assigned.
But if the directory part has been damaged already, our product can also detect data from
storage part directly, read all sector one after another, and try to rebuild every possible file.
All files found in this way are listed in RAW folder with a new file name like FILE001.
So you can also try to search desired data from RAW folder if the normal scan result
cannot satisfy you. Or you can configure a deep scan to detect data by reading deeply
into partition directory info or with the second copy of file table. But if the file still cannot
view completely in both scan results after the test, then we belive the file has been partly
damaged either in directory part or in storage part. It would be hard to get it back correctly this time.
