Hi,
Thanks for this calculator.
It's exactly what I was looking for, and I used it to help me figure some things out.
However, you have a bug in it.
Where you enter your own MTBF, by entering a Base 10 value.
It doesn't seem to react to that properly.
I wanted to use 1million, since I want to model a Seagate Ironwolf Drive, and that's the Manufacturer's suggested value.
But it gives me incorrect values.
Its' easy to see that without doing anything more, by using 1.2M and then 750k.
And what it gives for 1M is not in between that.
And then I got more complex, and put in a series of cases, and did a regression on the output.
And in fact it's a VERY nice fit.
I just did Raid 0, 1, 5 and 6.
If you plot MTBF on x-axis, and MTTDL on y-axis, then you get a perfect fit with: MTTDL = A_0 x (MTBF ^ A_1)
"Perfect" as in the R^2 is 1.00000
And there must be a relationship there, because the A-1's are related.
As in:
A_1 = 2.00 for Raid 0 and 1
A_1 = 1.00 for Raid 5
A_1 = 3.00 for Raid 6
With MTTDL in years.
And:
NRER = 10^14
Drive Capacity = 4TB
Sector Size = 512B
Disks = 5
Volumes = 1
Rebuild Speed = 100 MB/sec
The relationship for the A_0's is not so obvious:
Raid 0, A_1 = 2.13E-06
Raid 1, A_1 = 6.80E-08
Raid 5, A_1 = 1.18E-05
Raid 6, A_1 = 9.33E-10
And I suggest that you provide more space to see your inputs, it's too cramped.
At least on Chrome.
I'm now reading your Primer: I only saw it now....:-}
Thanks,
Alan
) boxes exhibit that behavior.
