Server data recovery environment & failure:
3 hard drives on a server form a raid5 disk array. While the server was running, the indicator light of a hard disk turned red, the RAID 5 disk array failed, and the partition of the server's upper operating system could not be recognized.
Server data recovery process:
1. Remove the disk number from the failed server. Hardware engineers conducted hardware fault detection on all disks. After testing, it was found that the three hard disks in the raid5 array could be recognized normally, and no physical bad sectors or other hardware faults were found.
2. Make a sector-level full-disk image of all disks in read-only mode. After the mirroring is completed, restore all disks to the original server according to their numbers. Subsequent data analysis and data recovery operations are based on the image files to avoid damaging the original disk data. Cause secondary damage.
3. Analyze the underlying data based on the image file, and obtain information related to the RAID structure such as the verification method and RAID disk sequence of the original RAID 5 disk array in the failed server by analyzing the underlying data. Virtually reorganize the raid5 array based on the obtained information about the raid5 structure and verify the reorganized array.
4. Verify the reorganized raid5 array data and try to extract the data from the raid5 array by setting each hard drive in the array to offline in turn. The extracted data is completely consistent. 
5. Check the virtually reorganized raid array data and find that some data in the server partition fails the verification.
6. Beiya Qian's data recovery engineer repaired the dat file on the server and verified the data again, and found that the backup file was still partially damaged. Continue to analyze the server & aggregate dat fragment files and find that the underlying structure is still partially damaged.
7. Scan the space page of the server partition and scan, extract, reorganize and verify the file fragments. After a long period of hard work, Beiya Qian's data recovery engineers successfully reconstructed all the data on the original server from the extracted fragmented files, and the data passed verification.
8. Build an environment consistent with the original server and connect to the database, and let the user verify the data. After verification by the user, it was confirmed that the recovered data can be loaded normally, and that the upper application software and the data in the software are all normal. The user approves the data recovery results. This data recovery work is completed.