You work as a design specialist at Certkiller .com. Certkiller .com plans to implement a new application. The application’s requires are as follows:
1. 85 IOPS sustained throughput per LUN
2. 2.19 Terabytes or storage
3. 4 HBAs
4. 40 LUNs
5. DMX Storage Array
Assume each physical 146 GB drive can sustain 170 IOPS, and that the application will perform approximately 25% writes and 75% reads.
What is the minimum number of physical mirrored drives (RAID 1) necessary to satisfy meet these requirements?
A.
20 Total drives
B.
30 Total drives
C.
40 Total drives
D.
60 Total drives
E.
80 Total drives
Explanation:
I/O calculation:
.75 * (85 * 40) 2250 + 2 * .25 * (85 * 40) 1700 = 3950 total I/O’s 3950 / 170 = 23 drives for I/O
Capacity calculation:
(2.19 * 1024) / 66.6 = 33.7 drives for capacity (R1 50% capacity so 133.33 / 2) Some hotspares and round up.