Specifically on external hard drives and flash drives, what is the process that makes your data degrade?

Will recopying it to the same drive "rejuvenate" the data, or is it the drive itself that is breaking down?

Never heard of data degrading.
Silicon will degrade in years.

As in long term data storage....what goes bad and why?

Here's a good paper about archiving data.

There are several considerations. Magnetic media demagnetizes; various technologies become obsolete and unusable (see the section about Zip drives); data may be stored in an obsolete format; the list is at least 10 items long.

most recommend a media update every 5 years or so for long term storage.

depending on the amount of data, this can be a bit cost prohitbitive, which is why a lot of large corps ignore the warnings and you get backups that don't work.

for personal storage, I keep 3 copies of everything.
blue-ray, nas, and second hard drive on the physical box I am on.
prevents loss of one item making it catastrophic.

now only certain things are backed up like that. but it is still a TB of data.

Not sure what degrades but this something I do........

Qhen storing data on an optical drive, I keep the original optical drive it was created on.

In the past I have pulled old optical disks only to find them somewhat unreadable in a new drive.

Pull out the original drive and I can read them just fine.

I transfer archived data from old media over to new every two years or so.

optical media degrades. just sitting around.

as said above magnetics like tape drives demagatize just sitting too.

flash is strictkly read and writes, however, you run into electronic componet failures as well.
both magnetic and componet failure relates to hard drives.

but the main killer as mentioned in the article and above, is tech changes making the media you chose obsolete.

for instance even on hard drives, pretty soon you won't have a pata connector avaible at all.
so if you have a drive from say 10 years ago, you would need an adapter pretty soon to even get it connected.

So, assuming the flash drive is still "mechanically functional"....and assuming there is still a functional PC with a USB port and the software that is relevant to the data on the flash drive,... any data on that flash drive will still be "readable"

Theoretically...



The thing about flash media is it has a limited number of reads and writes. The more it's used, the closer you get to reaching your max reads/writes. Also, the controller can go bad as well.

I don't know if they slowly degrade over time like a standard hard drive or optical media does. With CDs & DVDs, you have to worry about sunlight as well. Since I just recently lost a HD, I did some reading on how they work and their tolerances. Let's just say that I have a less than idealistic view about their reliability. There are so many things that can go wrong with a HD, not including the platters demagnetizing over time.



Overall, I think the advances in SSD technology is light years ahead of the basic optical media or HD. I read an article about someone putting a half-dozen new SSDs through a torture test. I believe they all had gone past 500tb in reads/writes and were still working fine. Even though some of the main blocks had worn out, the reserve blocks were working well.



There really is no magic pill when it comes to data storage for the home user unless you consider cloud technology. Of course, this is all relative depending on how much data needs to be stored.
 

yeah, that is a whole lot of what if's.

and it really depends on the time frame you are talking about.
10 years, sure. you probably can find all the parts you need to get a machine back up and running, or an emulator or an adapter to get data off something.
20 years, and now you will have some issues getting parts, adapters etc..
unless you keep the equipment sealed and powered off, there really is no guarantee it will fire up in any future run. sealed keeps any dust or bugs out of it. and humidity etc..

any more than that, and it is unlikely any new equipment will read it.

you look at flash drives as ubiquitous now. but floppy drives were too only 10 years ago, every computer came with at least the 3 inch floppies.
no computer comes with one today. 20 years ago, they all came with the 5 inch floppy drives too.
and yes some people keep working machines just to access this stuff. but it isn't cheap and it isn't easy.

moving to new media is more cost effective.

google bitrot