由於現今大規模分散式儲存系統不管在軟體或硬體經常地被使用，使得碰撞停止(Crash-Stop)與拜占庭故障(Byzantine Failure)越來越常發生。傳統的大規模分散式儲存系統大多是採取異地備援(Remote Backup)的方式，將資料備份並分開存放在兩地提供運轉服務。當其中一地的設備發生運轉問題，可以由另一地的設備繼續提供運轉服務，如此一來至少不會造成資料的遺失。但是在現今的時代，不少情形下的資料量是十分龐大的，這表示儲存資料的設備成本上升，甚至最糟可能兩地設備同時發生運轉問題，而再生碼(Regenerating Codes)已經被證實為能夠提供一個有效的分散式儲存系統及復原系統中故障節點的儲存資料的有效方法。
本篇論文主要是使用里德-所羅門碼(Reed-Solomon codes，簡稱RS codes)搭配循環冗餘校驗(Cyclic Redundancy Check，簡稱CRC)實現再生碼進行資料再生(Data Regeneration)以復原故障節點的儲存資料及發生拜占庭故障時進行資料重建(Data Reconstruction)的能力，並實現再生碼分別在最小儲存再生(Minimum Storage Regenerating，簡稱MSR)及最小頻寬再生(Minimum Bandwidth Regenerating，簡稱MBR)兩種條件下的運作情形。此外，不管在MSR 還是MBR 的條件之下，資料重建的部份會分別有兩種里德-所羅門碼解碼器進行重建的過程。最後會就儲存節點在不同故障率下進行比較，比較資料重建及資料再生的失敗率及所需訪問其他儲存節
點的個數。

Due to the today’s large-scale distributed storage systems are commonly built using commodity software and hardware, crash-stop and Byzantine failures are likely to be more prevalent. A common way to improve reliability of the traditional large-scale distributed storage systems is to take remote backup. The information is backed up and stored separately to provide operating services in two different places. When one of the devices has operational problem, services can be operated by another device. At least, the data will not loss by this approach. However, this approach is not suitable for large data storage. That main issue is the cost of the devices increases drastically. Also the worst case when both of the devices have operational problems in the same time is possible. Regenerating codes have been shown to provide a more efficient storage to large-scale distributed storage systems and can recover the information of the failed node efficiently.
In this thesis, we use Reed-Solomon codes (RS codes) and Cyclic Redundancy
Check (CRC) to achieve data regeneration, which recovers exact information of the failed node, and to achieve data reconstruction in the Byzantine failures. We also show the performance of the regeneration codes operated in Minimum Storage Regenerating (MSR) and Minimum Bandwidth Regenerating (MBR) points. In addition, two data-reconstruction methods are performed by RS decoder for MSR and MBR. Finally, we compare the average number of accessed nodes and fail rate of data reconstruction and data regeneration for different failure probabilities of storage nodes.

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