[server data recovery] a case of RAID5 data recovery of an EMC server

Server data recovery environment ：
EMC A certain type of server ;
20 Block hard disk composition raid5;
2 individual 45T Of lun.

Server failure ：
The administrator reinstalls the server , The server disk partition is lost due to unknown reasons , Lost partition storage important business information , The administrator contacts our data recovery center to recover the data of the server .

Server data recovery process ：
1、 The administrator brings the server to our data recovery center , After getting the server, the data recovery engineer mirrors all disk data to the backup server .
2、 The data recovery engineer uses the server data recovery tool independently developed by North Asia to analyze the mirrored data , Get... On the failed server raid Array disk sequence 、 Strip size, etc raid Information . By getting raid Virtual reorganization of information raid structure .
2、 restructuring raid After array, locate to xfs The starting location of the partition of the file system .
3、 check xfs The integrity and correctness of the file system ; The super block and some nodes of the file system header are found through verification 、 The directory entry is missing .
4、 Repair xfs The super block structure of the file system ; According to the super block backup and the directory tree structure in the file system , Repair and restore the super block .

5、 Yes xfs Repair the missing nodes and directory entries in the file system ; For missing nodes 、 The directory entry is patched 、 restructure .

 

6、 After the repair, the North Asia data recovery engineer writes a program to analyze xfs file system , Extract the data from it .

Server data recovery result analysis ：
Because of the super block and some nodes in the file system header of the server 、 The directory entry is missing , According to the super block backup and the directory tree structure in the file system , Repair and restore the super block , For missing nodes 、 The directory entry is patched 、 After refactoring , File system can be fully recovered .