Idis DA-ES1104 - Page 21

Part 3 - Conguration
21
RAID 5
The system saves data across three out of four hard drives installed, and an identical backup is created on the fourth
hard drive. Identical backups are spread across all hard drives. If one hard drive fails, the data can be preserved.
Therefore, it oers fast data transfer rate as well as data security. When four hard drives are used, total capacity of the
volume equals the total capacity of three hard drives. It is the most widely used method as it oers higher available
capacity than RAID 1+0 when used with 4 SATA hard drives.
Even if one of the hard drives fails, all data can be preserved. However, it is recommended that you replace the failed hard
drive and rebuild RAID volume as soon as possible.
1
4
7
3
4·5·6
8
1·2·3
6
9
2
5
7·8·9
HDD 1 HDD 2 HDD 3 HDD 4
1
2
3
4
5
6
Data