[server data recovery] data recovery case of a Huawei server raid6

Server data recovery environment ：

A Huawei brand server ;
10 Block hard disk composition raid6;
EXT3 file system , Divide 2 individual lun.

Server failure & analysis ：

The server is working raid6 Paralysis unavailable , Administrator's response to the failed server raid Rebuild and initialize raid, Initialization proceeds to 40% Initialization was forcibly stopped around , Some data have been seriously damaged . The administrator contacted our data recovery center after data recovery failed in several data recovery companies .

The reason why the server loses data is raid6 paralysis , The administrator then uses the original raid6 Medium 9 Hard disk construction riad5 And it has been initialized for a long time , This operation causes irreversible damage to the original data . The second is also proved in the later server data recovery operation LUN You can use the regular RAID6 Data recovery method recovers data , But the first place to store important data lun The probability of successful data recovery in is extremely low . Before our data recovery center received the failed server, many data recovery companies had conducted data recovery operations on the failed server , But they failed to recover the important data they needed .

Server data recovery process ：

1、 Mirror and backup all disks in the failed server .

2、 The server data recovery engineer analyzes the faulty server RAID6 Of RAID And disk organization , Analyze the newly built RAID5 Of RAID And disk organization . During actual operation, due to reconstruction RAID5 Lead to RAID6 and RAID5 A lot of underlying information overlaps , It is very difficult to analyze and distinguish these data , Service data recovery engineers spend a long time analyzing and distinguishing .

3、 The server data recovery engineer obtains the original through analysis raid6 And newly built raid5 Research on data recovery algorithm after information , It is found that the original data of the server can be recovered in other ways . The server data recovery engineer writes programs and correction algorithms , Set the server to raid6 The first and second of LUN Mirror to the two built storage respectively .

4、 Recover server data . The server data recovery engineer verifies the second LUN The data is completely normal , But the first one LUN A small part of the corrupted data in is extremely important .EXT3 The root directory of and the first block group I Nodes are all in this part of data , Server data recovery engineers try several commonly used data recovery software to scan and recover , But the effect is not ideal , It is estimated that this is the reason why the previous data recovery companies failed to recover data .

5、 In this case, the server data recovery engineer is responsible for the damage EXT3 Repair the file system . North Asia server data recovery engineer compiles a small program, right EXT3 File system for orphan directory search , Rebuild the root directory and I node , Using the file system parser to open it is completely normal , But in order to ensure the permissions and attributes of the original data , stay LINUX Make a simple repair under ,LINUX It can be mounted normally , And then from LINUX Copy the file to and format it as EXT3 On the partition of a single disk . So when users use data , No more settings are needed , The file directory structure and attributes are exactly the same as the original . The data recovery is completed , Data availability 100%.

The server Raid Suggestions for data protection after failure ：

1、 Do not bump the hard disk again , Any hard disk in the server is crucial for data recovery , If there is serious physical damage to the critical hard disk , Data recovery will become extremely difficult or even impossible .

2、 Never re create raid Or forced online/rebuild, If there is an early offline hard disk or online synchronization error in the server , It will lead to unpredictable data recovery effects and results .

3、 It is forbidden for non professionals to disassemble the main modules of fault storage 、 Replacement, etc , Improper operation will affect the internal data of the server , Even permanently destroy server data .