Which storage profile serves data the fastest for random disk IOPS?
A.
RAID-Z2
B.
RAID-Z3
C.
RAID-1
D.
RAID-ZR
E.
RAID-5
Explanation:
Using RAID-5
The conventional wisdom among database professionals is that RAID-5 is evil and should be avoided regardless of the situation. The primary issue with RAID-5 is that in addition to a parity calculation, each logical write requires many physical writes. The performance effects of this are most keenly felt on systems with a high write percentage, and are made worse in cases where there is not enough RAM. It follows that on systems with a low write percentage, and on those with sufficient memory, RAID-5 may not be such a performance killer as many make it out to be. The bottom line is that, depending on the IO profile and the storage implementation,
the performance difference between a RAID-5 and a RAID-10 array may not be discernable at all, and the extra costs of a RAID-10 array may be better spent elsewhere.
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