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

1. Server data recovery background

The server that needs data recovery this time is a brand CX4-480server, which consists of 20 hard raid5 disk arrays and two 45T lun. When the computer room administrator reinstalled the system on the server, the server disk partition license was changed due to unknown reasons, and the original sdc3 partition was lost, which stored most of the company's important business information, so there is an urgent need to restore the data of the server.

Second, server data backup

After a simple telephone communication between the server data recovery engineer and the client computer room administrator, it is estimated that the data can be fully restored after a simple understanding of the failure of the client server. Then the administrator brought the server to our data recovery center for initial server inspection and server data recovery. The data recovery engineer first mirrored all the disk data to the backup server. For later analysis and recovery of data.

Third, EMC CX4-480server data recovery process

1. Use the server data recovery tool independently developed by our center to analyze the raid array disk order, stripe size and other information on the mirrored customer data server. At present, the data recovery tool has not been released or sold to the public, and you can also search and view the FILE ID number through other versions of the data recovery tool on the market, and judge the disk array disk order, block size, loop direction, synchronous and asynchronous information in the server according to the number. (note: this operation has certain risks, and non-professionals are not recommended to try blindly. If the data is very important, it is best to find a professional data recovery company to operate. Through the virtual reorganization of the analyzed raid information, the raid structure is obtained.

2. Locate the starting position of the partition of the xfs file system after reorganizing the raid array; XFS INODE number: the number of digits with variable length, which consists of three parts: starting block group number + starting block number + intra-block INODE number. The bit lengths of the starting block number and the INODE number within the block are specified by the parameters in SUPERBLOCK.

3. Check the integrity and correctness of the xfs file system; through verification, it is found that the super block and some nodes and directory items in the head of the file system are missing.

4. Repair the super block structure of the xfs file system, repair and restore the super block according to the super block backup and the directory tree structure in the file system.

5. Repair the lost nodes and directory items in the xfs file system, repair and reconstruct the lost nodes and directory items.

6. Write a program to parse the xfs file system and extract the data after the repair is completed.

4. Server data recovery results

Because the super block and some nodes and directory items in the head of the file system of the server are lost, the super block is repaired and restored according to the super block backup and the directory tree structure in the file system. After the lost nodes and directory items are repaired and reconstructed, the file system can be completely restored. And because the customer did not do any destructive operations to write to the storage after the data was lost, most of the data and file system information remained intact, and the server data was 100% restored.

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