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How to calculate disk work load?
Can someone tell me the calculation, how to calculate?
An application created 4500 I/Os at peak workload with a peak work loads with read/write ratio of 2:1. What is disk load at peak activity for a RAID 6 configuration?
KEHutchinson
633 Posts
2
June 9th, 2016 07:00
Hi Arslan,
I ran your question by Sagar Patil, who manages the ISM curriculum. Here is his answer:
Can someone tell me the calculation, how to calculate?
An application created 4500 I/Os at peak workload with a peak work loads with read/write ratio of 2:1. What is disk load at peak activity for a RAID 6 configuration?
Peak workload = 4500 I/Os
Read/write ratio = 2:1
Therefore, reads = 2/3 * 4500 = 3000 I/Os
And writes = 1/3 * 4500 = 1500 I/Os
For RAID 6, write penalty is 6.
Therefore, Disk load = (3000 * 1) + (1500 *6) = 3000 + 9000 = 12000 I/Os
KEHutchinson
633 Posts
0
June 3rd, 2016 06:00
Hi Arslan,
Can you show how you are currently calculating the answer to this question?
Alp Arslan
34 Posts
0
June 4th, 2016 00:00
Hi Kate,
Really i dont know any formua or calculations about this question thats why i am asking. Please if you know calculation, let me know.
Alp Arslan
34 Posts
1
June 5th, 2016 00:00
Sorry for above calculation, as i did not calculate with 4500
66.66% reads of 4500 = 2997
33.33% Writes of 4500 = 1499.8
So Answer will be 11995.8
Alp Arslan
34 Posts
0
June 5th, 2016 00:00
Hy kate,
I found the solution and formula is "read+(write*write penalty)".
So above calculation will be
reads are 66.66% and writes are 33.33%
RAID 6 penalty is 6
Hence 66.66 + (6*33.33) = 66.66 + 199.98
Answer is 266.64