Raid 5 + Spare; Figure 40. Raid 5 - Data Striping With Striped Parity; Figure 41. Raid 5 + Spare - Intel SS4000-E - Entry Storage System NAS Server User Manual

Figure 40. RAID 5 - Data Striping with Striped Parity

RAID 5 + Spare

In a RAID 5 + spare configuration, three of the disks use RAID 5, and the fourth is empty.
If any of the three disks fails, it is immediately rebuilt using the fourth spare disk. As a
result, you can remove the failed disk and still have the ongoing fast performance and data
protection offered by RAID 5. When the failed disk is repaired or replaced and re-installed
into the storage system, it automatically becomes the spare for the other functioning three.
You can use RAID 5 + spare only if your storage system has four disks. If the disks are not
the same size, the smallest of the disks determines how much disk space is available for
data, similar to RAID 5.
®
Intel Entry Storage System SS4000-E User Guide
D1 D2
D3 P2
Disk 1 Disk 2
D1 D2
P2
D3
Disk 1 Disk 2
Spare

Figure 41. RAID 5 + Spare

P1
D4
Disk 3
AF000289
P1
D4
Disk 3
AF000291
Levels of RAID
171