[North Asia data recovery] data recovery case of database data loss caused by HP DL380 server RAID disk failure

Environmental Science ：
HP DL380 The server ;
Three pieces 300GSAS Hard disk ;
The database is D Partition ;
Backup on E Partition .

fault ：
A hard disk fails , The status light is red ,RAID paralysis , Storage failure ,D Partition is not recognized ,E Partitions are recognizable , Error in copying backup files . Restart the server , The hard disk offline first goes online , Synchronize data for a period of time , But force the shutdown before the synchronization is completed , I haven't touched the server since .

Data recovery process ：
1、 To ensure the security of data in the existing disk , The data recovery engineer of North Asia first makes a read-only image backup of the disk , Three hard disks can be read normally , There is no evil way , Read only mirror backup log .

      
2、 North Asia data recovery engineer makes a detailed analysis of the backed up image files , restructuring raid structure , And perform XOR verification , Part of the verification passed . Because the synchronization operation after the offline hard disk is online may damage the data , Partial pass means that the data is damaged ,

     
3、RAID The analysis process , Try to extract data when various hard disks are offline , The data extracted offline from each disk is the same ,

 

 

4、 North Asia data recovery engineers first aim at E In the division dat Analyze and repair the file . It is found that both backup files are damaged ,

 

5、 Data recovery engineers in North Asia analyze and aggregate dat debris , verification dat Data integrity , The underlying structure shows damage .

 

6、 At the same time D Analysis and scanning of partitioned data files , Due to storage synchronization , The data file directory is not visible .

7、 North Asia data recovery Engineer D Partition free space data pages for scanning , And analyze and aggregate file fragments .
8、 North Asia data recovery engineer verifies the integrity and effectiveness of data file fragments .
9、 Extract the data in the backup file and record it in the new database .
10、 Connect to the database through the upper application , Verify data availability , The database file can be loaded normally , The user account in the upper application software is normal , You can query normal data .

 

Data recovery results ：
In this data recovery process , stay E Disk discovery 2 individual SealLib Backup file of database . But a small part of the page structure in the backup file data is damaged , stay D Continuous data fragments are found in the results of partition scanning , Fragment available . Through to D Partition fragments and E Partition backup files for consolidation and splicing , The final repair of the parsed data can support the normal use of the entire application , The upper application can normally query the contents of the database .