Disk array multi-level fault tolerance method

Abstract

The invention provides a disk array multi-level fault tolerance method, which adopts a three-level fault tolerance mode to solve common array errors at present effectively. The first-level fault tolerance is sector-level fault tolerance for effectively preventing the vector incapable of tolerating fault of a disk from failing; the second-level tolerance is data migration-level fault tolerance for preventing fault caused by the reduction in the reliability of the disk; and the third-level fault tolerance is to apply a parallel reconstruction mode to repair the disk fault in an array quickly. In the method, the reliability of an array-based storage system is improved by a three-level fault tolerance policy, and the performance of the system is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of data storage, in particular to an array fault-tolerant method. Background technique [0002] The information produced in modern society, taking 2002 as an example, produced about 5 exabytes of information a year, of which 92% of new information was mostly stored in disks, and large-capacity disks have become an indispensable storage medium at present; important The storage of information such as company information is particularly critical. Research shows that 50% of companies have unrecoverable information for more than ten days, 43% of companies close down immediately after permanent data loss, and 93% of companies close down after serious data loss. Data reliability is especially important in data storage. The storage technology based on redundant array of independent disks (RAID) has been widely used in storage systems since its birth, because the storage system with RAID structure can guarantee the ...

AI Technical Summary

Problems solved by technology

The storage technology based on redundant array of independent disks (RAID) has been widely used in storage systems since its birth, because the storage system with RAID structure can guarantee the reliability of the system and the loss of data due to disk failure. Recovery, but with the continuous increase of modern disk capacity and disk, the data reconstruction time after disk failure will become very long. If a second disk failure occurs during this period, using the traditional RAID structure will result in loss of disk data. Data reliability will also face challenges, so reducing the secondary failure window can effectively avoid data loss

In addition if figure 1 As shown, the RAID 5 structure shown in the figure is composed of five data disks and one backup disk. If disk D2 fails, the system will read the remaining four disks participating in the formation of the array and calculate the failed data based on the verification information. , and then write it to the backup disk D5 to replace the current disk D2. In this process, it is not difficult to see that although multiple reconstruction processes can be started, the backup disk D5 will become the writing bottleneck of the reconstruction process. For example, for For a disk with a disk capacity of 1TB, if the reconstruction speed is 50MB / s, and only offline reconstruction is considered, the reconstruction time will be about 6 hours. The long process restricts the performance of the system. It also poses challenges to the reliability of the system

[0003] On the other hand, although disk drive manufacturers are improving the performance parameters of their products, various errors in the disk itself still pose a threat to system reliability, especially the phenomenon of disk data loss caused by disk sector errors has become very serious

Images