What are the odds of 20 hard drives failing at once?

[itfitzme]

Here you go, the definitions of independent events and conditional probabilites.

Dependent and Independent Events

The occurrence of some events may affect the probability of occurrence of others. For example, the complementary events A and A cannot occur simultaneously. If one took place the other is out of the game:


P(A|A) = 0
regardless of the probability P(A). (P(A|B) denotes the conditional probability of A assuming B.) We say that the event A is not independent of the event A (assuming P(A) ≠ 0 of couse.) And, in general, an event A is not independent of an event B iff P(A) ≠ P(A|B), i.e., if occurrence of B affects the probability of A. It may not be obvious right away, but the relationship "not independent" is symmetric: if A is not independent of B then also B is not independent of A. Formally,


if P(A) ≠ P(A|B) then P(B) ≠ P(B|A).
To see why that is so we invoke the defintion of conditional probability,


P(A|B) = P(A∩B) / P(B),
so that P(A) = P(A|B) implies P(A∩B) / P(B) = P(A), or


P(A∩B) = P(A) P(B),
which also may serve as the definition of independency of A from B. But the later relationship is symmetric! It implies


P(B) = P(A∩B)/P(A) = P(B|A),
which exactly means that B is independent of A. We see that two events A and B are either both dependent or independent one from the other. The symmetric definition of independency is this

(*)
P(A∩B) = P(A) P(B).
Two events A and B are independent iff that condition holds. They are dependent otherwise.



Dependent and Independent Events

Does that help any?

 

[Jughead]

What are the odds of 20 hard drives failing at once?

Not as good as me winning the powerball.

 

[itfitzme]

How about,

HDD manufacturers typically specify a Mean Time Between Failures or an Annualized Failure Rate (AFR) which are population statistics that can not predict the behavior of an individual unit.


...an HDD can fail at any time in many different situations.

https://en.m.wikipedia.org/wiki/Hard_disk_drive_failure

 

[itfitzme]

What are the odds of 20 hard drives failing at once?

Not as good as me winning the powerball.

What did you use for MTBF?


What did you use for the hours of operation?

 

[bripat9643]

Harddrives have ratings for expected loss of data integrity measured as Mean Time Between Failures (MTBF.) Modern harddrives have MTBFs in the millions of hours of continuous power on. So the odds of 20 harddrives all failing at the same time is:

MTBF x MTBf x MTBF... times 17 more. In other words, as with top tier hd comanies like Western Digital with MTBFs of 1 million hours, the chances of 20 drives faling at the same time is once per life age of the Earth. Or there abouts.

that's not how it works.

Yes it is, moron. You obviously failed pre-calculas.

 

[bripat9643]

They aren't just any random hard drives. They are likely to have been purchased from the same manufacturer, manufactured at the same time, shipped with the same shipping carrier, and installed by the same people, even person.

That's actually not true. You are assuming they were all hired on the same day and received their equipment on the same day.

 

[mamooth]

Why is everyone wasting time trying to calculate the odds of a conservative conspiracy theory?

Do like I do. Point out how the conservatives are just proudly making shit up again. It's a habit they have.

 

[Jughead]

What are the odds of 20 hard drives failing at once?

Not as good as me winning the powerball.

What did you use for MTBF?


What did you use for the hours of operation?

The elapsed time between failures here is not relevant. The odds that 20 hard drives could all fail around the same time is ludicrous. Anyone who falls for it, is more than welcome to purchase a bridge that I have for sale in Brooklyn.

 

[itfitzme]

Here is something from PC World.

Study: Hard Drive Failure Rates Much Higher Than Makers



However, the study showed typical annual replacement rates of between 2% and 4%, "and up to 13% observed on some systems."

Study: Hard Drive Failure Rates Much Higher Than Makers Estimate | PCWorld

 

[itfitzme]

Not as good as me winning the powerball.

What did you use for MTBF?


What did you use for the hours of operation?

The elapsed time between failures here is not relevant. The odds that 20 hard drives could all fail around the same time is ludicrous. Anyone who falls for it, is more than welcome to purchase a bridge that I have for sale in Brooklyn.

Also relevant is " Five hundred and fifty eight million hard drives were shipped in 2009."

558,000,000 per year.

 

[itfitzme]

Why is everyone wasting time trying to calculate the odds of a conservative conspiracy theory?

Do like I do. Point out how the conservatives are just proudly making shit up again. It's a habit they have.

Because it is the OP, I've seen this same consideration come up before and it wasn't answered. I thought I',d give it another go.

And the answer is../

However, the study showed typical annual replacement rates of between 2% and 4%, "and up to 13% observed on some systems."

Between that and the 580 mil sold per year we can gauge something.

 

[JimBowie1958]

If they came from the same unit, possible, still very unlikely. Thus, the need for hard copies.

Plus federal law states they have to keep permanent records of emails.

Simple fact, and the IRS is violating the law by not doing so.

But if people are willing to believe that 20 HDs are all going to fail at the same time, they will believe anything.

The odds of winning the jackpot with a $1 ticket are 1-in-13,983,816.

And, amazingly, some one manages to pick five winning numbers.

And if you understood mathematics you would know that the odds we are talking about regarding the HDs are far lower than winning five lottery tickets in a row.

We are talking about odds so incredibly small that you have a better luck shooting at the moon, literally.

The likelihood that you can figure out what the actual odds are for 20 hard drive failures, even lower.

Did it already, moron.

The odds that you will figure out why your question is irrelevant, even lower stll.

What does it matter 'why' you think your lies will have any relevance? You make things up like the HDS all being from the same batch as though that would explain anything, when the point is that you will believe anything the Dimbocrap leaders tell you, because yes, you are just that stupid, gullible or dishonest, take your pick.

You little Nazi goose-stepping fucktards are losing day by day because you have no respect for Truth, you have no integrity and you smell like a used car salesman even over your internet connection.

roflmao

 

[JimBowie1958]

Why is everyone wasting time trying to calculate the odds of a conservative conspiracy theory?

Do like I do. Point out how the conservatives are just proudly making shit up again. It's a habit they have.

Because it is the OP, I've seen this same consideration come up before and it wasn't answered. I thought I',d give it another go.

And the answer is../

However, the study showed typical annual replacement rates of between 2% and 4%, "and up to 13% observed on some systems."

Between that and the 580 mil sold per year we can gauge something.

But we aren't talking about just 20 HDS out of the whole fucking market, idiot.

We are talking about a specific set of 20 HDs all that tie in with emails from/to Lerner about using the power of the IRS to harass and intimidate the Tea Party, and the central message you guys on the Dim left is that you don't give a fuck about how Obama abuses the office of the Presidency. As long as he is your dictator you are just peachy keen with all of it.

But lets take the god-awful 13% failure per annum. That is roughly 1:8 of failing, and of 20 HDs failing all in the same period of time, the same year, is 8^20th power, which is roughly 1 in 1,152,921,504,606,846,976; one in a quintillion.

[ame=http://www.youtube.com/watch?v=nswpM1W1APs]One Quintillion pennies - YouTube[/ame]

The chances of the worst HDs having 20 out of 20 all fail in the same year is about the same likelihood of someone saying the found the only penny in that huge stack at the end of the video above that had their initials on it by blowing the whole thing up and finding that that specific penny had landed out of the blue in their cup sitting on the ground at their feet.

You obviously do not understand the math here, and it doesn't matter. It's the only lie you've left to you and so you will run with it till the cows come home.

 

[Care4all]

Plus federal law states they have to keep permanent records of emails.

Simple fact, and the IRS is violating the law by not doing so.

But if people are willing to believe that 20 HDs are all going to fail at the same time, they will believe anything.

The odds of winning the jackpot with a $1 ticket are 1-in-13,983,816.

And, amazingly, some one manages to pick five winning numbers.

And if you understood mathematics you would know that the odds we are talking about regarding the HDs are far lower than winning five lottery tickets in a row.

We are talking about odds so incredibly small that you have a better luck shooting at the moon, literally.

The likelihood that you can figure out what the actual odds are for 20 hard drive failures, even lower.

Did it already, moron.

The odds that you will figure out why your question is irrelevant, even lower stll.

What does it matter 'why' you think your lies will have any relevance? You make things up like the HDS all being from the same batch as though that would explain anything, when the point is that you will believe anything the Dimbocrap leaders tell you, because yes, you are just that stupid, gullible or dishonest, take your pick.

You little Nazi goose-stepping fucktards are losing day by day because you have no respect for Truth, you have no integrity and you smell like a used car salesman even over your internet connection.

roflmao

The irs in the first 6 months of this year, has had 2000, that's 2 thousand, hard drive crashes....

and I will ask, please TELL US YOUR THEORY on 20 hard drives crashing in a 2 year period...

Do you think these 20 hard drives were PURPOSELY CRASHED back in 2009 and 2010 and 2011? Do you think these employees went in individually and managed to blow up their own hard drives back then? Or do you think the computer technologists blew up these hard drives for these 20 people?

and WHY do you think these people of the 20 hard drive crashes blew up their own hard drives back then?

What is it that YOU THINK they were trying to hide back in 2009, 2010, and 2011? Or are these hard drives that blew up from 2012-2014?

HOW ABOUT SOME FACTS behind your speculations and conspiracy theories so we all can ponder with you?

So again, what is your THEORY on these hard drive crashes...spell it out.

If this is your conspiracy theory, what do you have to support it?

 

[JimBowie1958]

Why is everyone wasting time trying to calculate the odds of a conservative conspiracy theory?

Do like I do. Point out how the conservatives are just proudly making shit up again. It's a habit they have.

That lie is so stupid. Anyone can read the news and see that the IRS admits that they violated the law by not storing the emails as legally required, and that the approximately 20 HDs of all the people the Congress has subpoenaed have all crashed just like Lerners did.

That is the obvious lie, and that is the lie you PC Nazis goose-stepping bastard will repeat to your last breath despite how idiotic the claim is.

But you also toss in a generic sweeping claim that everything anyone says to criticize Obama is presumably a conservative (not true, btw) and that they are just lying.

You are a moron, too stupid to even bother to make up believable lies anymore.

 

[JimBowie1958]

The odds of winning the jackpot with a $1 ticket are 1-in-13,983,816.

And, amazingly, some one manages to pick five winning numbers.

And if you understood mathematics you would know that the odds we are talking about regarding the HDs are far lower than winning five lottery tickets in a row.

We are talking about odds so incredibly small that you have a better luck shooting at the moon, literally.



Did it already, moron.

The odds that you will figure out why your question is irrelevant, even lower stll.

What does it matter 'why' you think your lies will have any relevance? You make things up like the HDS all being from the same batch as though that would explain anything, when the point is that you will believe anything the Dimbocrap leaders tell you, because yes, you are just that stupid, gullible or dishonest, take your pick.

You little Nazi goose-stepping fucktards are losing day by day because you have no respect for Truth, you have no integrity and you smell like a used car salesman even over your internet connection.

roflmao

The irs in the first 6 months of this year, has had 2000, that's 2 thousand, hard drive crashes....

and I will ask, please TELL US YOUR THEORY on 20 hard drives crashing in a 2 year period...

Do you think these 20 hard drives were PURPOSELY CRASHED back in 2009 and 2010 and 2011? Do you think these employees went in individually and managed to blow up their own hard drives back then? Or do you think the computer technologists blew up these hard drives for these 20 people?

and WHY do you think these people of the 20 hard drive crashes blew up their own hard drives back then?

What is it that YOU THINK they were trying to hide back in 2009, 2010, and 2011? Or are these hard drives that blew up from 2012-2014?

HOW ABOUT SOME FACTS behind your speculations and conspiracy theories so we all can ponder with you?

So again, what is your THEORY on these hard drive crashes...spell it out.

If this is your conspiracy theory, what do you have to support it?

The facts are already out there, you godamned fascist.

This is not about all the HDs in the IRS. We are talking about every one of the people Lerner had been communicating with about the Tea Party harassment all had their HDs crash for that same period, something they did not bother to tell anyone till the judge ruled they had to give the emails over.

That doesn't require some elaborate conspiracy theory, all it requires is the realization that the Dimbocrapic Party will lie rather than lose the election, stone wall as long as possible and then trust their party members to lie, lie and lie some more to cover up their criminal activities.

And you are one of them, obviously, and like a good goose-stepping fascist soldier, you will lie right along with them and hope you can find some other issue before the elections get here.

 

[Marianne]

None You all are being haunted by a dead player who didn't make the team and is pissed.

 

[AceRothstein]

A 20 person fantasy football league? Would never happen.

 

[Care4all]

Why is everyone wasting time trying to calculate the odds of a conservative conspiracy theory?

Do like I do. Point out how the conservatives are just proudly making shit up again. It's a habit they have.

That lie is so stupid. Anyone can read the news and see that the IRS admits that they violated the law by not storing the emails as legally required, and that the approximately 20 HDs of all the people the Congress has subpoenaed have all crashed just l ike LErners did.

That is the obvious lie, and that is the lie you PC Nazis goose-stepping bastard will repeat to your last breath despite how idiotic the claim is.

But you also toss in a generic sweeping claim that everything anyone says to criticize Obama is presumably a conservative (not true, btw) and that they are just lying.

You are a moron, too stupid to even bother to make up believable lies anymore.

The irs set up a system that they could afford at the time, which was backing up emails on servers for 6 months, once an employee reached 1800 emails they were told to go through their active emails and delete those unnecessary and archive the rest of them on each individual's hard drive....THIS IS THE WHOLE IRS, 90,000 employees....not just the tax exempt division of Lois Lerner's...

So, the IRS or the Treasury Secretary, who the irs reports to, decided for the entire agency to do it this way....did it break their own rules and regs, probably, but supposedly they were short on money and at the time, did not have the 10,000,000 dollars to buy a server large enough in their budget. A SLAP ON THE HAND, for them not finding a way to afford it!

But WHAT DOES ANY OF THIS have to do with this conspiracy that Lerner and Obama collaborated together to squash only the Tea Party's applications for tax exempt status which allows the BIG donors to be hidden in darkness and to take a tax write off for the donations to politicians and political causes?

So once again, what is your conspiracy theory about these 20 hard drives? what do you think happened? spell it out and spell out why you think it happened...pretty please.

And / or do you think the IRS is lying about the hard drive crashes?

Kind of hard to do since hard drive crashes and computer replacements are documented at the time of the crash....

 

[JimBowie1958]

A 20 person fantasy football league? Would never happen.

The last one I was in had 16 players, and that was enough.

I lost interest that year when the secretary won with an impressive record and she said her secret was that she picked the guys with the cutest names, i.e. Slavic or foreign looking unusual names.

Thought she was joking till I looked over her roster again.

Why waste your time when that kind of thing can happen?

lol