How long can you read files from a flash drive if kept in a cool, dark room?

Question

Say you had some sensitive information that you didn't want to store on the internet, was incredibly important to you, and you didn't need to access very often either.

Think of a digital picture taken of your grandma days before her death or something... Very important stuff.

So you load the file to a flash drive, put it in a vault, and forget about it.

When should you re-visit the vault to back-up the data to a newer, futuristic flash drive or whatever they are using to store data with in the future.

What are the chances that the data will have dissappeared or the flash drive become unreadable in 5 years? 10 years? 25 years? 100 years?

Answer 1

I think that with the current technologies the limiting factor will not be the amount of time the data will be able to be stored on the media without decaying, but the availability of readers. It is hard nowadays to read a 5 inch floppy disk, and almost impossible to read the stack of 50+ years old perfectly preserved punch cards left from my grandmothers education in the university.

So I think you should change the device with more modern every 10 years or so just to be sure.

Answer 2

Flash cells are... fairly stable. I'd say in the order of a decade or more. But if you want truly long-life media then you should look to OTP (one-time programmable) media such as PROM or EPROM. Unfortunately I'm not aware of any available in a USB format though, so you would probably have to drop down to using bare chips and a programmer.

And of course, don't forget the 3-copy rule.

Answer 3

All of the prior mentioned are good points, but if I were you, I would not trust only one copy of backup of this sensitive data especially on a flash device. I have had them fail in the past. Storing the data on a small external hard drive actually places the data on the magnetic platter, in this way EVEN if the hard drive fails, you can have experts repair or retrieve the data. Even in this case I would not leave it on the drive untouched for over 10 years, as hard drives are also susceptible to bit decay.

If you have the money your best options are to get a glass die made for imprinting either DVD's or CD's with the data you want, as this is an actual physical representation of your data. I also know that there is a company somewhere that will etch your binary data onto gold plates for the ultimate lifespan.

Tape backup is another time-tested solution except the readers and media can get expensive.

I personally use a device like this as because it stores the data with RAID 1, a mirror onto both hard-drives, so in case one fails, you can rebuild the data... and if both fail, the experts have twice the hard drives to retrieve data from.

Lastly, I would consider using a printed binary copy of your data. There is a “joke” (though functional) open-source project called PaperBack which includes such features as compression and redundancy that will allow you to print your data as 2D barcodes onto actual sheets of paper and store them in your safe.

The reason I mention all of these options is because lets say you store a flash drive in your safe, AND a burned cd AND a tape backup.. and your house burns down. The temperatures exposed to this safe will cause the flash drive, cd, tape, etc to melt and be useless (even with expert recovery people). Paper copies or etched glass will be more resilient to this type of damage.

Lastly I would put my data in the 'cloud', amazon offers data store with a free 5GB start I believe. Also a company called dropbox has a VERY convenient and cross platform syncing system with cloud storage starting free at 2GB

Answer 4

I agree with D.Iankov regarding changing the media every 10 years, or as you see that your current media appears to be aging compared to new technology, as well as the availability to be able to use the old technology, you would want to change it then.

As far as a current media, a flash drive, while very stable overall, they are still more subject to failure when compared to a DVD. I would use a DVD burner and put them on DVD. The estimates for DVD life vary greatly from 20 years to 200 years. If you store them in a cool dark location, I would think you would get at least 50 years out of a good quality disk, but again, you will need a reader in the future, and that may be tough to get in 50 years.

I also agree with keeping multiple copies in different locations if the data is extremely valuable. I have seen backups fail, and the only thing that saved the company was having multiple copies. I have also had a company (as a consultant) burn down, and they were not good about taking a tape off-site weekly, so they lost all their data.

http://www.audioholics.com/education/audio-formats-technology/cd-and-dvd-longevity-how-long-will-they-last

http://www.guardian.co.uk/technology/askjack/2008/may/08/howlongshouldadvdlast

Answer 5

Everybody has been very correct in pointing out that flash drives are very durable if stored correctly.

Then why am i posting yet another answer?

The reason is that no matter how good you store your flash drives, they will eventually need to be read, somewhere. Now that they are plugged in, they can be destroyed by a variety of causes. Sudden buildup of static electricity, poor power supply, logic failure, operating system failure, et cetera, et cetera.

Thus, remember, if you want to make sure you store it properly, make multiple copies, at multiple places, in multiple formats. I would have taken a master-grade CD (e.g. one from Taiyo-Yuden), a SD card, a USB drive, and/or something else, and put it in two different safes if it were so important to me.

Good luck!

Answer 6

Paper is still the (easily created) format that holds up best over time. Properly stored paper can be read for thousands of years.

Any modern digital format should be refreshed frequently (with the value for frequently determined by the media type.) I would refresh any VERY important data at least annually and keep three copies in separate locations.

Answer 7

Print a hard copy, get it laminated, put it in the vault. It should still be there and readable in 100 years. Storage media and software codecs could become obsolete in 100 years, but I doubt that copiers or scanners will become obsolete anytime soon.