Shulou(Shulou.com)06/02 Report--

The emergence of GPT is to replace the old MBR (Master Boot Record), which mainly solves the problem that MBR partition tables do not support partitions whose capacity is larger than 2.2TB. Although Microsoft has vigorously promoted the windows10 operating system and announced that it will no longer update the win7 system, win7 users are still a large group. If the computer uses Windows 7, it must adopt the MBR partition format, so that the original disk partition table in the hard disk is lost and the data in the disk can not be read normally due to the misoperation and conversion of different partition tables. The problem that the data in the hard disk can not be read and used due to the problem of GPT partition table is more prominent.

Due to a variety of data loss problems caused by the conversion of GPT and MBR, although we can quickly recover user data with the help of some commonly used data recovery software, the research on computer technology is the spirit that we always need to maintain and continue to pursue.

Recently, we received a case of ST500DM002 about the loss of partition data caused by misoperation. We learned from the user that there were four partitions on the hard disk, all of which had important data. Through the fuzzy recollection of the customer, combined with the engineer's bottom analysis, it is roughly determined that the error operation deleted the partition and then want to retrieve the data, as a result, the hard disk partition structure was converted into MBR by mistake. This means that we can use common software such as Rmurs and DG to restore partition data. In addition, we can also completely restore the original GPT partition by modifying the underlying layer.

It is well known that when the GPT partition table is deleted, the partition information will be emptied and the location will be covered by the partition information of the existing partition. For the MBR partition structure, DG software has the function of "searching for partition loss (rebuilding MBR)" for partition loss, but because there is information such as a global unique identifier in the GPT partition structure, there is no effective direct recovery of GPT partition structure in both manual recovery and software recovery. (partition table check and GPT header check can be calculated)

So now we see that there is only one invalid partition, as shown in the following figure:

However, by searching for key bytes, you can locate the start and end of the original partition. The partition information is as follows:

It is found that the data in these logical partitions are intact, and the original GPT header backup is also there. in order to restore the original partition structure, we need to "deceive" the computer and recreate the partition according to the searched partition information, so that the computer mistakenly thinks that the partition information created is the same as the original partition size. But you need to pay attention to only create the operation in this process, do not format it.

First of all, modify the partition structure of the hard disk to GPT partition, and then create the partition corresponding to the size. The process of creation is the process of "rebuilding the original partition table". After being created in turn, the original partition DBR backup found by the searched key bytes is used to replace the created partition DBR, so that the purpose of manually rebuilding the original partition structure can be achieved. So far, manual complete repair of the damaged GPT partition has been successful.

Complete user data:

This data recovery instance is accidental, and the degree of damage is more serious in most recovery cases. This type of fault is difficult to achieve complete repair when some key locations are covered, deleted and rebuilt many times. The recovery example of this paper is a good practice of in-depth exploration of data recovery technology, and the actual recovery work should focus on customer data and make a technical attempt under the condition of ensuring data security.

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