系统内冗余或重复数据的度量，表明存储和潜在性能问题效率低下。
1 DF = 0.6 PB
1 PB = 1.667 DF
例子:
将15 数据折叠转换为奇偶校验的冗余：
15 DF = 9 PB
| 数据折叠 | 奇偶校验的冗余 |
|---|---|
| 0.01 DF | 0.006 PB |
| 0.1 DF | 0.06 PB |
| 1 DF | 0.6 PB |
| 2 DF | 1.2 PB |
| 3 DF | 1.8 PB |
| 5 DF | 3 PB |
| 10 DF | 6 PB |
| 20 DF | 12 PB |
| 30 DF | 18 PB |
| 40 DF | 24 PB |
| 50 DF | 30 PB |
| 60 DF | 36 PB |
| 70 DF | 42 PB |
| 80 DF | 48 PB |
| 90 DF | 54 PB |
| 100 DF | 60 PB |
| 250 DF | 150 PB |
| 500 DF | 300 PB |
| 750 DF | 450 PB |
| 1000 DF | 600 PB |
| 10000 DF | 6,000 PB |
| 100000 DF | 60,000 PB |
规则