Dell PowerVault MD1120 Optimization Manual page 28

A REFERENCE GUIDE FOR OPTIMIZING DELL™ POWERVAULT™ MD1XXX FAMILY SAS SOLUTION VER A02
RAID 1
A RAID 1 solution, while not ideal, could be utilized for small workgroup servers or servers with low
storage capacity and growth requirements. Any server beyond a small workgroup server is likely to
need more storage and consequently, a more efficient RAID solution.
RAID 10
RAID 10 has good I/O performance, excellent availability and redundancy. The biggest drawback
of RAID 10 is that it requires twice the number of physical disks needed for data. This RAID
configuration should be used in situations requiring maximum availability, redundancy, and
performance.
RAID 5
RAID 5 has good I/O performance, data protection and requires only one additional physical disk
than the number needed for data. RAID 5 should be used in situations where maximum storage
capacity is required along with a moderate amount of data protection.
RAID 50
A balance between RAID 5 and RAID 10, this solution offers good I/O performance, availability and
good storage capacity. This configuration offers slightly higher performance than RAID 5, but
requires multiple additional physical disks than the number needed for data. It does however
provide greater storage capacity than a RAID 10 solution with a decrease in performance and data
protection. This should be used in situations where greater redundancy and data protection is
required as well as a reasonable storage capacity.
RAID 6
RAID 6 has adequate I/O performance, enhanced data protection and requires only two additional
physical disks than the number needed for data. RAID 6 adds an additional level of redundancy
over RAID 5 with the ability to sustain 2 drive failures per RAID set. RAID 6 should be used in
situations where maximum storage capacity is required along with a high amount of data
protection.
RAID 60
A balance between RAID 6 and RAID 10, this solution offers good I/O performance, availability and
good storage capacity. This configuration offers slightly higher performance than RAID 6, but
requires multiple additional physical disks than the number needed for data. It does however
provide greater storage capacity than a RAID 10 solution with a decrease in performance and data
protection. This should be used in situations where greater redundancy and data protection is
required as well as a reasonable storage capacity.
Note: For more details on RAID configurations see the Dell 'Getting Started with RAID' document
(http://support.dell.com/support/edocs/storage/RAID/RAIDbk0.pdf)
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