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What is the probability that an external back-up drive will fail?

And how would you minimize that probability?

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migrated from Aug 28 '10 at 17:34

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External backup drives don't have fans. In my experience, the fail at a rediculously high rate. As a matter of fact, I have never had an internal drive fail, and had both of the external drives fail on me. I stopped buying them after that. I have however had much more luck with the solid state external drives, like the Iomega Ego. – aepryus Aug 28 '10 at 17:05
@aepyus hope you knocked on wood when you typed "i have never had an internal drive fail" – Chris Aug 28 '10 at 17:10
when you drop it (more likely with a portable external drive than with an internal drive) it will fail earlier... – Andre Holzner Aug 28 '10 at 17:24

No formula .. but it depends on your usage and how you take care of your drive.External backup drive is nothing bus same as internal HDD but covered in a case and with USB interface. So it all depends on how you keep it safe.

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There is both a science and formula to hard drive failure. Most hard drive manufacturers will publish a "mean time between failures" as part of the technical specification for the disk. (Because hard drives are often manufactured by one company, used by another to make an external drive, and sold by yet another, this information can be tricky to track down.) See this article on Wikipedia for more information on the science and formula in engineering:

Note that I'm not trying to criticize the initial two posts. I believe "oooo" and "Anil Vishnoi" are accurate when they say that the time to failure is impacted significantly by external failures. If you dropped your desktop once a week for a month, something would probably break rather quickly.

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So, what is that probability? – Adam SU Aug 31 '10 at 13:45
@AdamSU The probability is 0.42 – Craig Young Jul 1 '12 at 15:37

No exact science. But usual disk failures we have observed are within the first few months of a disk purchase. If it gets through that and no failures, you're good to until year two or three involving daily moderate desktop user usage.

However, it also depends on how valuable your data is. It is guaranteed to fail if it is your only copy of highly valuable data... :)

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My Seagate FreeAgent Xtreme started developing problems after about a year.

To this day, I have to unplug it during a boot so it doesn't keep the box from starting.

On the rare occasions that it does boot with the drive attached, it won't be present in the OS unless I unplug & re-plug it in again.

Seagate support has been no help. First said I had to test it on another computer before they'd take action.

By the time I got another computer to test it on, it was out of Warranty, so I'm SOL anyway.

No data loss yet, but I'm uneasy with it for sure.

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Use a regular 3 inch drive in an Antec MX-1 external case. comes with silent fan, usb and e-sata connections. I have 12 Tb in 6 enclosures. for images of my six pcs. I've had no failures in 3 years

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