基於現今的資料容錯機制，都是把資料和產生出來的校驗碼放在同一組硬碟上，也就是說，當使用者想採取不同的資料容錯機制的時候，就必須使用新的一組硬碟。這樣的情況下，造成硬碟空間利用低，而且在硬碟的數量有限下，使用者無法使用兩種以上的資料容錯技術。

本論文在單機電腦上，以檔案的位置作為區分，實施了兩種不同的資料容錯技術。而且讓使用者在有限的硬碟數量下，更加彈性地決定對資料的存放，並且讓資料的重要性由使用者自己來定義，藉此在硬碟的空間利用率和校驗碼計算速度之間取得一個平衡。

Nowadays, the data fault-tolerant technique is to put data and erasure code in the same disk group. When a user would like to use another data fault-tolerant technique, he must use a new group of disks. In the situation, the disk utilization is very low, and a user cannot manipulate more than two kinds of data fault-tolerant technique with finite disks.

This thesis constructs a hybrid data fault-tolerant system by distinguish the different location of files in a stand-alone computer. A user can decide how to store data elastically, and define the importance of data by himself, for getting a balance between the disk utilization and the execution speed of erasure code calculation.

第一章 介紹 1
第二章 背景介紹 3
2.1 Raid機制 3
2.2 LRC機制 4
第三章 系統架構 6
3.1系統概觀 6
3.2裝置映射 7
3.3 ext4檔案系統的程序流程 8
3.4區塊層的程序流程 9
3.5硬碟位置映射 11
第四章 實驗 12
4.1系統規格 12
4.2實驗數據 12
第五章 結論 14
附錄 15

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