HP Smart Array 6i Controller and 128MB BBWC - Manual (Page 48)

48 HP Smart Array 6i Controller User Guide
Item RAID 0 RAID 1+0 RAID 5 RAID ADG
Relative cost Low High Medium Medium
*NOTE: Values for usable drive space are calculated with these
assumptions: (1) all physical drives in the array have the same capacity;
(2) online spares are not used; (3) no more than 14 physical drives are
used per array for RAID 5; and (4) no more than 56 drives are used with
RAID ADG.
Selecting a RAID Method
NOTE: Not all controllers support RAID ADG.
Most Important Criterion Also Important Suggested RAID Level
Fault tolerance Cost effectiveness
I/O performance
RAID ADG*
RAID 1+0
Cost effectiveness Fault tolerance
I/O performance
RAID ADG*
RAID 5 (RAID 0 if fault tolerance is not required)
I/O performance Cost effectiveness
Fault tolerance
RAID 5 (RAID 0 if fault tolerance is not required)
RAID 1+0
Alternative Fault-Tolerance Methods
Your operating system may also support software-based RAID or controller
duplexing.
•
Software-based RAID resembles hardware-based RAID, except that the
operating system works with logical drives as if they were physical drives.
To protect against data loss caused by physical drive failure, each logical
drive must be in a different array from the others.
•
Controller duplexing uses two identical controllers with independent,
identical sets of drives containing identical data. In the unlikely event of a
controller failure, the remaining controller and drives will service all
requests.
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