Developers Guide

12 Understanding RAID with Dell SC Series Storage | 3104-CD-DS
RAID levels have different attributes for performance, reliability and rebuilds and are described in Table 4.
The first column lists the RAID level while the other columns indicate the best suited workload along with
rebuild performance and relative protection.
RAID level and redundancy comparison.
RAID
Reads
Writes
Redundancy
Relative
protection
Rebuild
performance
Random
Sequential
Random
Sequential
10
Excellent
Excellent
Excellent
Excellent
Single
Excellent
Best
10-DM
Excellent
Excellent
Good
Good
Dual
Best
Best
5-5
Excellent
Excellent
Good
Excellent
Single
Good
Good
5-9
Excellent
Excellent
Good
Excellent
Single
Good
Good
6-6
Excellent
Excellent
OK
Good
Dual
Best
Good
6-10
Excellent
Excellent
OK
Good
Dual
Best
OK
Note: RAID performance and relative protection are directly affected during rebuild and reconstruction. RAID
reconstruction times increase substantially as physical disk sizes increase. The time for reconstruction
increases the potential for a second disk failure which exposes the vulnerability of the data on the array.