Shulou(Shulou.com)06/03 Report--

Brief introduction to server data recovery failure:

What needs to be recovered is a HP DL380 server with three 300GSAS hard drives that form a raid array. The disk failure paralyzes the entire RAID group, and the status light of one hard disk is red. The database is stored in partition D and the backup is stored in partition E. Storage failure, resulting in the D partition can not be identified, E partition can be identified, but copy the backup file reported an error, and restart the server, resulting in the first offline hard disk online, and synchronized for a period of time, directly forced shutdown without synchronization completed, and then did not move the server.

Server data recovery process:

In order to ensure the security of the original data of the server, first make a read-only mirror backup of all the disks in the server, three hard disks can be read normally, no bad paths are found, and only read the mirror backup log.

Figure 1:

Make a detailed analysis of the backup image file, reorganize the raid structure, and perform XOR check. Some of the checks pass. After the offline hard disk is online, the synchronization operation will damage the data, and partly pass means that the data is damaged.

Figure 2:

In the process of RAID analysis, try to extract data from various hard drives offline, and the data extracted from each disk is the same.

Figure 3:

First of all, analyze and repair the dat file in E partition. Both backup files were found to be corrupted

Figure 4:

Analyze the aggregated dat fragments to verify the integrity of the dat data, and the underlying structure shows damage.

Figure 5:

At the same time, the data files of partition D are analyzed and scanned, and the data file directory is not visible due to storage synchronization.

Figure 6:

Scan the free space data page of partition D, and analyze and aggregate the file fragments.

Verify the integrity and validity of data file fragments.

Extract the data records from the backup file to the newly created database.

Through the upper application to connect to the database to verify the availability of data, the database file can be loaded normally, the user account in the upper application software is normal, and the normal data query can be carried out.

The server data was recovered successfully:

During the recovery process, 2 backup files of SealLib databases were found on disk E. However, a small part of the page structure in the backup file data is damaged, and more continuous data fragments are found in the results of the D partition scan, and the fragments are available. Through the integration and splicing of D partition fragments and E partition backup files. The final repair of the parsed data can support the normal use of the whole application, and the upper application can query the database content normally.

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