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This article mainly explains "how to restore XenServer server SQL Server database data", the content of the article is simple and clear, easy to learn and understand, now please follow the editor's ideas slowly in depth, together to study and learn "how to restore XenServer server SQL Server database data"!

Environment:

Dell PowerEdge server

XenServer Virtualization platform

RAID10 consisting of 4 raid cards for Seagate 2T STAT hard drives

XenServer virtual machine operating system: Windows Server system

Virtual machine disk: 1 10G system disk and 1 5G data disk, deployed Web server (ASP + SQL).

Fault:

The sudden power outage of the server led to the unavailability of a XenServer virtual machine in the server and the loss of virtual disk files. The server administrator contacted the North Asia data recovery Center for help.

Fault detection and analysis:

1. After getting the original data disk, the North Asia data recovery engineer connects the original disk to the North Asia data recovery server and prepares the space exceeding the total capacity of the original disk to be used as backup data. The original disk is mirrored to the backup space in the way of the underlying sector of the disk, and later operations are performed on the backup data to ensure the data security of the original disk.

2. After analyzing the underlying data, the North Asia data recovery engineer found that the disks of virtual machines in XenServer are stored in LVM structure, that is, the virtual disk of each virtual machine is a LV, and the virtual disk mode is reduced mode.

The relevant information of LVM is recorded in Xen Server. Looking at the relevant information of LVM under "/ etc/lvm/backup/frombtye.com", it is found that there is no damaged virtual disk information, so the North Asian data recovery engineer judged that the information of LVM has been updated. Therefore, North Asia data recovery engineers can only continue to analyze the bottom layer to see if they can find the LVM information that has not been updated, and after some efforts, they finally find the LVM information that has not been updated at the bottom.

As shown below:

3. Find the area where the virtual disk stores the data according to the unupdated LVM information obtained, and find that the data in this area has been destroyed. After analysis by North Asia data recovery engineer,

It is found that the reason for the unavailability of the virtual machine is that the virtual disk of the virtual machine is destroyed and the operating system and data in the virtual machine are lost. This situation is most likely caused by malicious programs left behind by the virtual machine after a network intrusion. After carefully checking this area, North Asian engineers found that although a lot of data in the area was destroyed, they still found a lot of page fragments of the database, and they could try to piece together the page fragments of these databases into a usable database.

Server data recovery process:

1. Data recovery plan 1

According to the idea of scheme 1, according to the structure of RAR package, we can find the data start location of many packages, and the file name of this RAR will be recorded in the first sector of RAR file. Therefore, the start location of the backup database package can be found by matching the file name of the backup database archive that is learned from the administrator to the file name of the location of the archive currently found. After finding the location of the compressed package, carefully analyze the data in this area, then restore the data in this area and rename it to a compressed file in RAR format, try to extract the compressed package and report an error.

The error is shown in the following figure:

After a careful analysis of the recovered compression package, the North Asia data recovery engineer found that some of the data was corrupted, so an error was reported during decompression. Try using RAR's repair tool to see if you can ignore the error and extract some of the data. As a result, after the completion of the repair, the extracted data was only part of the code of the website, and no backup files of the database were found. Therefore, you can judge that the database backup file is corrupted in the RAR package.

The following is the extracted part of the website code:

2. Data recovery plan 2

Because the scheme did not recover the database successfully, the second scheme was adopted to recover the data. Analyze the starting position of the database at the bottom according to the structure of the SQL Server database. In the structure of the SQL Server database, page 9 records the database name of the database. So after learning the database name from the server administrator, the North Asia data recovery engineer analyzes the underlying layer and finds the starting location of the database. Because the database page number and file number are recorded in every page of the SQL Server database, the North Asian data recovery engineer writes a program to scan the data that matches the database page according to these characteristics.

Then reassemble the scanned fragments into a complete MDF file in order, and then check whether the whole MDF file is complete by the MDF check program.

The rebuilt MDF file is as follows:

Verify the data:

After testing and determining that the recovered data is all right, the North Asia engineer sets up the database environment, attaches the reorganized database to the built database environment, and queries whether the relevant table data is normal and whether the latest data exists.

The screenshot is as follows:

Because the database needs to be combined with the website code to better verify the integrity of the database. The administrator took the website code from the website developer to set up the environment, and then configured the recovered database to verify it. No problems were found, and the data recovery was successful.

Thank you for your reading, the above is the content of "how to restore XenServer server SQL Server database data". After the study of this article, I believe you have a deeper understanding of how to restore XenServer server SQL Server database data, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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