White Papers
Table Of Contents
- 1 Introduction to member RAID policies
- 2 RAID policy availability and performance comparisons
- 3 Setting the member RAID policy
- 4 Displaying the RAID level space distribution
- 5 PS Series array disk layout
- 6 Converting or migrating from a member RAID policy
- 7 Summary
- A 12-Disk PS Series array RAID configurations
- B 14-Disk PS Series array RAID configurations
- C 16-Disk PS Series array RAID configurations
- D 48-Disk PS Series array RAID configurations
- E 42 or 84-disk PS Series RAID configurations
- F Technical support and resources
29 Dell PS Series Storage: Choosing a Member RAID Policy | TR1020 | v 4.7
Surviving disk failures with RAID 50 as the member RAID policy
C.2 RAID 5
Figure 18 shows that RAID 5 provides capacity and protection from disk failure but less availability for a 16-
disk, PS6000 array. RAID 5 provides less availability because there is only one set and one spare. This level
of RAID is not recommended for any production PS Series arrays.
In the following figure, the member RAID policy is RAID 5 with spares. Spares and RAID protect the data.
Surviving disk failures with RAID 5 as the member RAID level
C.3 RAID 6
Figure 19 shows that RAID 6 provides capacity and protection from single or dual disk failures for a 16-disk,
PS6000 array. RAID 6 provides less availability because there is only one set and two spares. This level of
RAID is best used with larger physical disk sizes and for data that requires the highest level of protection and
reliability.
In the following figure, the member RAID policy is RAID 6 with spares. There is only one spare in a 16-disk
array with RAID 6. RAID and the spare disk protect the data. Even after the spare is used, the RAID set can
survive the failure of any two disks at the same time.