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Old 2022-01-19, 13:43   #100
Dr Sardonicus
 
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Speaking of human life expectancy... MTBF: A Complete Overview
Quote:
Misunderstanding MTBF

One of the biggest misconceptions about MTBF is that it is the same thing as the number of operating hours before failure or "service life." If you get an extremely high MTBF number (not uncommon), you might think there's no way the system can operate this long without a failure. The reason for high MTBF numbers is because they are mostly based on the asset's rate of failure when that asset is still in its "normal" or "useful" life, assuming it will fail at that rate forever. It's for this reason there should be no correlation between service life and MTBF. You can have a piece of equipment with a very high MTBF but a low expected service life.

A good example of this is laid out by Wendy Torell and Victor Avelar in their whitepaper Mean Time Between Failure: Explanation Standards using human beings. Say you have 500,000 25-year-olds in a sample population. Over the span of one year, data is collected on failures (deaths) for this population. The population's operational life is 500,000 x 1 year = 500,000 people years. Over the course of the year, 625 people failed (died). This brings the failure rate to 625 failures / 500,000 people years = 0.125% / year. So, our MTBF is 1 / 0.00125 = 800 years.

This shows us that, even though 25-year-old humans have high MTBF values, their life expectancy (service rate) is a lot shorter and doesn't correlate.
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Old 2022-02-09, 17:17   #101
storm5510
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The little portable drive I allowed to hit the wall is still operating normally. It must have been in sleep mode when it fell, spun-down. I ran some rather rigorous tests on it after the drop. It has been 23 days since. No problems with it at all.

When I go grocery shopping, I make a point to tour the electronics department at Walmart. Two days ago, they had six WD external drives on the shelf, "My Book" is the name, I believe. Four were 6TB and two were 4TB. Yesterday, I found I needed a filter for my furnace. So, I went back. All the WD's were gone. I ask the individual behind the counter about it. He said, "They go fast." I asked about the three Seagate externals collecting dust. He told me that no one wants them because they have a tendency to fail after a few weeks, and that many had been returned. It would seem space-based crypto has caught on here.
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Old 2022-02-09, 17:27   #102
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Quote:
Originally Posted by Dr Sardonicus View Post
Speaking of human life expectancy... MTBF: A Complete Overview
"though 25-year-old humans have high MTBF values, their life expectancy (service rate) is a lot shorter and doesn't correlate."
Contrarily, one can observe, service life << max observed MTBF. Max MTBF provides a loose upper bound.


Quote:
Originally Posted by storm5510 View Post
It must have been in sleep mode when it fell, spun-down. I ran some rather rigorous tests on it after the drop.
Fall detection and a quick head park during the fall has been commercially available for nearly 20 years. https://www.analog.com/en/analog-dia...rd-drives.html

Last fiddled with by kriesel on 2022-02-09 at 17:31
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Old 2022-02-09, 17:28   #103
chalsall
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Quote:
Originally Posted by storm5510 View Post
I asked about the three Seagate externals collecting dust. He told me that no one wants them because they have a tendency to fail after a few weeks, and that many had been returned. It would seem space-based crypto has caught on here.
LOL about the "let the market decide" empirical wrt Seagate. Personally, I won't touch the brand unless I have no other choice.

BTW... It /might/ not be PoS crypto alone. High-end video production, for example, produces MASSIVE amounts of data!
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Old 2022-02-10, 00:56   #104
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Quote:
Originally Posted by storm5510 View Post
WD external drives on the shelf, "My Book" is the name, I believe.
Both WD Elements and WD MyBook (and in the states WD Easystore as well) external HDDs are worth picking up if you need some storage.

Typically* they come with "white label" WD Red drives inside, but for less than a bare WD Red drive costs.
* Not always, there was a furore a while back for 4 - 8 TB drives where I think they used SMR drives and people complained about poor performance.

I've had a few MyBook/Elements drives and shucked them, now they are internal drives and running happily.

FWIW, I also stay away from Seagate drives.

Edit: Also WD external drives tend to go on fairly big discounts semi-regularly on Amazon (and possibly other retailers). So if you kinda need some storage, but not urgently, it's worth waiting around until they dip.

Last fiddled with by lavalamp on 2022-02-10 at 00:58
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Old 2022-02-11, 17:48   #105
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Quote:
Originally Posted by chalsall View Post
...BTW... It /might/ not be PoS crypto alone. High-end video production, for example, produces MASSIVE amounts of data!
I have a Sony HandiCam which uses tapes. I have had it since the early 2000's. It has features which newer digital models do not have. I have a USB dongle to capture the video with. The format the capture software writes to a drive is MPEG. Those can get huge in a hurry. I only have a single battery for the camera, and it will still take and hold a charge. Back when I used it a lot, there were not many alternate data types, like MP4, to convert them to. A video utility called "Handbrake" can take a multi gigabyte video and drop it down to around 700 MB and write it as an MP4 with very little loss in quality.

I burned up a hard drive back in those days, literally. I was trying to process video on a P4 system with maybe 2 GB of RAM. I do not remember what the software platform was called which I used. This was in the 32-bit Windows XP days. As the processing called for more RAM, the visible GUI would be written to a swap-file on the HD. All of that was drive thrashing in the extreme. When the video processing was finished, the GUI was drawn back like a window-shade being pulled down very slowly, from top to bottom. The drive would thrash doing this as well. One day, it all stopped, and the screen went blank. I knew the drive had failed because I could smell it. I had to use a glove on one hand to remove it because it was too hot to touch with bare fingers. It was a Maxtor drive. 400 GB, if memory serves.

People in these parts like their sports, which is mostly basketball and a little high-school wrestling. I can easily see some storing large amounts of video in its native format. I did not think that many large drives would sell so rapidly.

Sorry for going a bit off-topic and rambling so...
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