[North Asia data recovery] data recovery case of XFS file system server with lost disk partition after system reinstallation

Time:2022-6-2

Server data recovery environment:
XFS file system server;
Md1200 disk cabinet +raid card +linux system;
Riad5+ about 80t LUNs divided into two partitions;
The 2T SDC1 partition is added to the root through LVM expansion_ LV;
The sdc2 partition is an XFS file system.

Server failure:
After the server reinstalls the system, the SDC disk partition is changed. The original sdc2 partition is lost and cannot be accessed. The administrator contacts the North Asia Data Recovery Center for data recovery.

Server data recovery process:
According to the conventional recovery process, the server is first backed up in read-only mode. The North Asia data recovery engineer returns the original server after making a mirror backup of each disk, and performs data analysis and data recovery operations on the backup data.
1. Analyze the image file to find the hard disk order, stripe size and other information of the server RAID disk array;
2. North Asia data recovery engineers use the data recovery tools developed by North Asia to virtually restructure the RAID array and virtually restructure the raid structure;
3. Locate the starting location of the partition of the XFS file system in the virtual reorganized RAID array;
4. Verify the integrity and correctness of the XFS file system. After verification, the North Asia data recovery engineer found that the file system was normal;
5. Repair the super block structure of XFS file system;

[North Asia data recovery] data recovery case of XFS file system server with lost disk partition after system reinstallation
Repair completed superblock

6. The North Asia data recovery engineer repairs the missing nodes and directory entries in the XFS file system;

[North Asia data recovery] data recovery case of XFS file system server with lost disk partition after system reinstallation
Repair completed root node

[North Asia data recovery] data recovery case of XFS file system server with lost disk partition after system reinstallation
Redo catalog entry

7. After the repair is completed, the data recovery engineer of North Asia writes a program to parse the XFS file system and extract the data in it.

[North Asia data recovery] data recovery case of XFS file system server with lost disk partition after system reinstallation
Repair completed directory structure

Data recovery results:
During the server data recovery, the data recovery engineer of North Asia detected the lost XFS file system and found that the super block, some nodes and directory entries in the file system header were lost. North Asia data recovery engineers repair and restore the super block according to the super block backup and the directory tree structure in the file system. After repairing and reconstructing the lost nodes and directory items, the data in the file system can be successfully recovered.
Since no other operations were performed on the server after the data was lost, the data and file system were saved to the greatest extent. After the data analysis and data recovery operations of the data recovery Engineer in North Asia, all the data in the server was finally completely recovered, and verified to be correct by the server administrator. This data recovery was successful.