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When selecting a RAID level for your system, consider the following factors.
RAID
Data
Level
Redundancy
0
No
1
Yes
10
Yes
Physical drive utilization, read performance, and write performance depend on the number of
drives in the array. Generally, the more drives in the array, the better the performance.
RAID 0 (Non-RAID Arrays)
An array with RAID 0 includes two or more disk drives (maximum twelve) and provides data
striping, where data is distributed evenly across the disk drives in equal-sized sections.
RAID 0 arrays do not maintain redundant data, so they offer no data protection. However,
compared to an equal-sized group of independent disks, a RAID 0 array provides improved
I/O performance.
Drive segment size is limited to the size of the smallest disk drive in the array. For instance, an
array with two 250 GB disk drives and two 400 GB disk drives can create a RAID 0 drive
segment of 250 GB, for a total of 1000 GB for the volume, as shown in the following figure.
Disk Drive 1
250 GB
Disk Drive 2
250 GB
Disk Drive 3
400 GB
Disk Drive 4
400 GB
Disk Drives in Logical Drive
Physical
Drive
Capacity
Read
Write
Utilization
Performance
Performance
100%
Superior
Superior
50%
Very high
Very high
50%
Very high
Very high
Drive Segment Size (Smallest Disk Drive)
Disk Drive 1
1
5
Disk Drive 2
2
6
3
Disk Drive 3
7
Not Used
4
Disk Drive 4
8
Not Used
RAID 0 Logical Drive = 1000 GB
Appendix B: Understanding RAID
Built-In
Min Number
Spare Drive
of Drives
No
No
No
997
...
998
...
999
...
Unused Space: 150 GB
1000
...
Unused Space: 150 GB
59
●
Max Number
of Drives
1
4
2
2
4
4
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