Simple data recovery in Windows Server getting started

During daily use of the computer, files may be accidentally deleted due to misoperations or other causes. Although these accidentally deleted files cannot be read through conventional methods, however, it may still be restored through some special means, which is called data recovery.
Data Recovery is a basic skill that must be mastered during computer maintenance. First, let's take a look at why deleted files can be recovered.

 

I. Basic principles of data recovery

We all know that the first thing to store data on a hard disk is to divide the hard disk into a category and a sector, that is, to perform low-level formatting on the hard disk. The slice is the minimum physical storage unit of the hard disk. The storage space of each slice is B.
Since the current hard disk capacity has reached hundreds of GB, the number of sectors in the hard disk has almost become an astronomical number. It is difficult to manage so many sectors. To further improve the Read and Write efficiency, multiple adjacent slices are designed to be combined and managed in a Windows system. These combined slices are called clusters.
A cluster is a logical concept. It does not exist on a disk, but is the smallest storage unit in Windows. For example, if you create a new text file in a partition of the hard disk and enter a number "a" in it, you will find that the file size is only 1B, but the disk space is 4 kb, 4 kb is the size of the disk partition cluster. Each cluster contains eight sectors.

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Because only one file can be stored in a cluster, the remaining space in the cluster is wasted. As to whether a cluster contains several slices, it is determined during the advanced formatting of the disk partition. By default, the size of each cluster is 4 kb.
A cluster is a basic unit for data storage in Windows. Each cluster has a number. A file allocation table exists in each disk partition. The file allocation table records the number of clusters in which each file in the partition is stored. To read a file, the system first needs to find the file allocation table and obtain the specific storage location of the file before finding the corresponding file.
When a file is deleted, the file storage records in the file allocation table are deleted, and the cluster occupied by the file is marked as idle, the file itself is still stored in the original cluster. In this way, the deleted file cannot be found in the file allocation table through the normal method, so the file disappears, some special software can be used to read files stored in the cluster. This is the basic principle of data recovery.

After understanding the principles of data recovery, we can consider whether the lost data can be restored in the following situations?

L a deleted file, and the recycle bin has been cleared.

L a partition after advanced formatting.

L when performing the Ghost restoration operation, it was supposed to be restored to drive C, but it was restored to drive d Due to misoperations. Can the original data in disk D be restored?

The answer is that the lost data can be recovered in the first two cases, while the data in the third case is mostly unrecoverable. The reason is that a data write operation occurs on the Ghost, which overwrites the original data on the d disk. In this case, it is difficult to recover the data. Of course, the premise that the data can be restored in the first two cases is that you must not write any new data to the partition where the deleted file is located or to the formatted partition, otherwise, the original data may be overwritten and cannot be restored.

 

Ii. data recovery practices

Common data recovery software include EasyRecovery, FinalData, and DiskGenius. DiskGenius, as an excellent hard disk tool in China, not only has powerful hard disk partitioning functions, it also has good results in data recovery. For data recovery software, it is recommended that you use the green version of the software, and it is best to put it on a USB flash drive and other mobile devices to avoid writing data to the hard disk.
The following uses DiskGenius3.8 as an example to describe the data recovery process.
Open the VM, drag DiskGenius to the drive D of the VM, and then drag a Word document and an image file to the drive E of the VM for testing.
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Delete all two test files and open DiskGenius. Select the partition edisk where the deleted file is located, and click "Restore file" on the toolbar to open the file recovery dialog box.

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In the restore file dialog box, select "Restore deleted files by mistake ".
If the partition where the file is located has a write operation after the file is deleted, it is best to check the "extra scan for known file types" option at the same time, click "select file type" to set the file type to be restored. When this option is selected, the software scans all idle space in the partition. If you find files of the type to be searched, the software lists these files in the "all types" folder. In this way, if the deleted files cannot be found in the normal directory before deletion, you can find the files in "all types" based on the file extension.
Because the file type is slow to scan (all idle sectors need to be scanned), we recommend that you do not use this option to search for it once in normal mode. If you cannot find the file to be restored, use this method to scan again.
If you do not select "extra scan for known file types", click "start" to start the search process. After the search is complete, you will find two deleted files.

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Select the two files, right-click the files in the file list, and select the copy to menu item. Next, select the folder for storing the recovered files. To prevent secondary damage to the partition being restored by the copy operation, DiskGenius cannot restore the file to the original partition. Here, we choose to restore the file to drive C.
Open the recovered files to drive C and find that all data is intact. So far, the data recovery operation has been completed successfully.

 

 

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