Shulou(Shulou.com)06/01 Report--

This paper introduces many data recovery cases of server class. Today, from the point of view of virtual machine data recovery, the editor introduces a successful data recovery case in which the virtual machine cannot be started due to abnormal power outage. It involves not only virtual machine data recovery, but also server data recovery, database repair and other technical knowledge.

One of the customer's virtual machines can not be started due to abnormal power outage of the server. the customer virtual machine is based on a well-known brand of EVA8400 server hardware and uses the ESXI5.5 operating system. The data in the virtual machine is the database.

After the customer virtual machine could not be started, the server was restarted, but the virtual machine still could not be started. Because the customer data was classified, we had to contact the professional data recovery operation.

The data recovery engineer went to the customer site for data recovery detection and found that the user's virtual machine had two snapshots, merged the two virtual machine snapshots and opened the image file of the virtual machine in disk format for analysis. After analysis, it is found that the internal data of the file system has been cleared, replaced and other forms of file data have been lost, and the index file of the database has been replaced.

Data recovery process:

The main data in the customer virtual machine is the database file, so as long as the database file in the virtual machine is extracted, the data recovery of the virtual machine can be completed. Because the mysisam engine of the database uses independent table space to store data, that is, the data of each table is stored independently. Therefore, when the index file is destroyed but the file exists, the database file can still be recovered by analyzing the underlying data. Through the analysis and repair of the customer image file, the database engineer finally extracted the database file data, and after the data recovery engineer rebuilt the virtual machine, the data was still partially destroyed. it is predicted that this part of the data can not be repaired because of the abnormality in the tablespace of the system.

Contacting the customer for on-site verification of the data indicates that about 3% of the data in the virtual machine has not been successfully recovered, but the important data in the database has been successfully restored. 3% of the failed recovery is secondary data, the customer recognizes the result of this data recovery, and the virtual machine data recovery is successful.

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