Hard drives aren't rated for 30 years, though. Even in optimal conditions, they'd deteriorate.

proper archiving is surprisingly difficult, esp the time capsule idea. maybe this gets you started

https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html

Hard drives that aren't used will get data errors over time. Usually for data storage this is counteracted with what's called a "scrub" every so often (like few months). This just means the whole drive content is read, and the drive itself will figure out if any areas have a "weak signal", and just rewrite that part.

Having only 1 drive without any mirror and without any way to detect potential errors (let alone a way to correct them) is a recipe for disaster.

I think if you want 10+ years with high assurance you probably want to burn the data to archival quality BD-R disks (not the dye based ones)

The right spinning platter hard drives might have a decent chance to make it 10 years but there's a lot of possible failure modes and also a decent chance that when you try spinning it back up it gives nothing but read errors.

For cases for "only" 10-30 years I might pick a pelican-like case inside a makeshift wooden coffin-like outer layer. For longer I'd probably use a metal box like an ammo box inside the plastic case and a stone outer layer instead of wood

You must have an amazing porn collection. You can store it on my NAS

A much better medium would be tape back up, or possibly Blu-ray discs. Either one would last a lot longer than a hard drive.

If this is a real problem you have, and not just a thought experiment, I think rather than burying the data on some unreliable medium, your best bet is to just pay someone to store it for you offshore, away from the dictatorship you mentioned.

There are plenty of consumer-grade cloud storage services. I'm sure there are more niche ones specifically for long-term archival as well, which would usually be cheaper per bit, per-year, if you don't need to access the data regularly.

So much data has already been lost due to bitrot caused by magnetic loss and plastic breakdown. Most consumer grade storage will break down and start to lose data within a decade. Even if the data survives, will the operating system and software be available in the future to read the media? Surprisingly, the best way to preserve data long term is to print it on paper. Or write it to a gold record and send it into space.

I’d go with optical media here. Probably multiple capsules.

• M-Disk (DVD if it will fit, otherwise Blu-ray)
• Make an encrypted archive of your data. Strong password - I suggest diceware with 8 or more words so you might remember it in 30 years
• Use DVDisaster to add parity data. You sacrifice some space, but you get error tolerance in exchange
• Wrap the disks up in good jewel cases, well sealed plastic, along with some good big silica gel desiccant packs.
• Put all that in the smallest durable, airtight container you can
• stash somewhere it probably won’t be disturbed for a few decades. Memorize.
• destroy all evidence you did this.

I'm going to buck the trend here and suggest a really physical storage medium: Print your data out. Or laser engrave it onto sheets of metal or polymer, or whatever you want to do. If you just print pokey old black and white ones and zeros as square pixels on a sheet of 8.5x11" paper at a humble 72 DPI you can store a shade under 47 kilobytes per page without having to resort to any additional trickery. Maybe a kB or two less if you need to leave margins. How much data are you really trying to store?

In a sealed container in the dark you could easily make paper last hundreds of years (we have perfectly intact books sitting on ordinary shelves from the 1800s already), and if you wanted to print on Tyvek or something it'd probably endure thousands.

Reading this back would not be a plug-and-play solution but would have the added advantage of being a purely optical process rather than having to interface with antique storage device electronics on whatever computer you may be using 30 years from now. All you'd need is sheet feed scanner or in a pinch any sufficiently high resolution camera, and the ability to run some kind of programming environment to run a script to read those pixels back into file data.

Maybe this wouldn't be great for archiving your collection of 4k ultra-definition porn, but it'd be absolutely sufficient for storing text and executable data for small programs, plans and schematics, other knowledgy sciency data, and even images... with the added benefit of, if any gestapo thug happens to find this early and dig it up he won't be able to ascertain what that image is just by looking at the piece of paper.

Sorry if this is obvious to everyone, but how would having a hidden hard disk help with living in a dictatorship?

Couldn't you just let someone in another country take care of archiving it?

You could look at fire safe boxes for document storage. Those are usually pretty solid. You would want to bag up the drive inside an anti static bag and probably put a couple of those little water absorbing silicone packets in there as well. If access isn't an issue then maybe some sealant around the seams to keep it more water tight.

Magnetic tape would be better for long term storage as well I think. Those have longer storage stability. I don't know how long an unplugged hard drive will reliably store information.

Animals could dig it up but probably wouldn't as it wouldn't smell like food. Depth wise I'd go for at least a couple feet deep, the traditional 6 is a surprisingly deep hole and temperature gets more consistent the deeper you go (at least with readily available tools, it eventually starts to get hot again).

Please note totally random opinion with very little experience with long term data storage. Thanks for the fun thought experiment, I hope things get better and you don't need your backup data.

My take -- OP is an anti-authoritarian time traveler. Go get em! I hope your data stays safe.

P.s. - want to drop me some winning lottery numbers? My dms are open

They key is to diversify. Use different types of storage media, and duplicate your efforts and bury then duplicates somewhere else.

~~If you can choose only 1 I would choose tape archives.~~ Vacuum seal all your media, whatever they may be. Throw in some of those dehumidifier packets. Moisture will be your biggest enemy.

If possible, also add the means to be able to read your media after a long time. Add a couple of raspberry pi computers, vacuum sealed and dehumidified-by-packets again, and usb readers or HATs for the media you chose (though I doubt you will find a cheap tape drive with USB connection, the only option I found was £9000).

Over the years, as new technology gets developed, in particularly interface connectors that will replace USB, I would add converters if possible or just keep them around. Nothing suspicious about having some USB/sata/sas to converter in your house.

Or, you know, you could always go with m-disc. Burners are cheap (40€ to 160€) and discs are cheap (4x 100GB costs 100€). For potentially 140€ you could store 400GB on a solid solution. Would still add a reader and devices as described above.

i think your best bet would just be to brute force it: get a bunch of different media (usb-drives, CDs, hard drives, whatever you can get your hands on and ideally from different brands) and just put the same data on all of them, then wrap in a series of plastic bags that you try to put a vacuum on, put in the most durable water and ideally airtight container you can get your hands on, then again wrap that in some plastic bags because why not.
Then bury all that as deep as you can and surround it in rocks, especially i think you'll want a bunch of rocks on top of it. And for extra points repeat all this as many times as possible in different locations.

All this is just to compound the chances that at least one of the copies of the data will survive, and even if that fails you'll hopefully end up with enough data being intact across the different storage mediums that you can piece the data together somehow, i'm not sure how precisely you'd do that but it's at least possible to figure out so long as the data is there.

If it's small you might try printing the files on archival paper with archival ink. Then you can put copies in multiple safe deposit boxes. Also you could bury copies rolled up in plastic water bottles. I think those are unlikely to degrade anytime soon. Or glass bottles with plastic lids.

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

Don't bury it. And don't count on ten years. Thirty years guarantees the media won't be physically compatible with future devices. How would you read a floppy disk from 1995 today? You'd be able to find a USB floppy drive, probably, online. Good luck having the disk be in a format that a modern OS understands. You'd need specialty software for that.

Get two spinning disk drives from major brands like Western Digital or Toshiba (not Seagate, for sure). Get different brands to reduce risk of failure from a manufacturing issue (as in, two from the same batch are likely to have the same failure if there was a production issue).

Send one somewhere abroad where it can be stored in a safe deposit box (hopefully, you know someone who lives in a free-er country). Plan to exchange it with a freshly written drive every three years. Go back and forth like this, completely rewriting the data each time to minimize the chances of bit-rot (look up this term to understand why you're rewriting and exchanging the drives).

This will also address files formats that evolve and eventually become incompatible with future software (thinking proprietary things, not plain text, jpegs, or standardized media files). I did something similar having a family member store music that I recorded (my own, not ripped CDs) in a different state in case of natural disaster at home.

All of this can be done pretty cheap. $200 bucks should cover both drives and at least a couple of years of physical storage at a bank. International shipping will probably be the biggest cost, especially over time.

The issue with hard drives is that they tend to fail even on ideal conditions and even when powered down. Yes I've lost very important data to a powered down hard drive.

While it's possible to recover information on a hard drive as long as the plates themselves aren't damaged, that requires very expensive specialised tools and skills. Which probably wouldn't be available in a scenario where the information on the drive would be of any value.

DVD-R (and probably consequentially Blu-Rays) aren't any better in my experience, I've lost more data to DVD-R than to hard drives actually. Even when stored in low light conditions they tend to just stop reading.

However optical media has one big advantage here, is that the discs themselves are cheap, so instead of having all your digital eggs in the same basket, you spread them over several discs and while some information may be lost, others may survive.

Now, here's an interesting thought, with digital data, the data either reads or doesn't read, the so called digital cliff, may become partially corrupted and other parts still read, but after the corruption gets past a certain threshold all information is lost.

With analogue equipment even after severe signal degradation the contents while very deteriorated may still be perceptible, forwardermore an analogue signal is much easier to decode in the event that you need to restart ~~civilisation~~ building tech from scratch and don't have access to the very very specific specifications of something like the audio codec or the filesystem.

You can probably hack a rudimentary cassette player together from very simple components, all you need is a tape head (a coil), a motor (a coil and a magnet), and an amplifier (a transistor or vaccum tube). (I'm probably oversimplifying here).

Overall I think the most important thing is having redundancy, or if redundancy isn't possible at least don't have all eggs in the same basket, instead of having everything in a single 8TB HDD, to try spread them into smaller 512GB ones, or DVDs or flash drives or all of the above. And don't store them all in the same location, if an area gets flooded or someone builds a building on top, you're only losing a small part of the information.

I have a question. Is this for you in the future, or for someone who may find it? If it's the latter, and it's just information you want to store, not media, I'd just go with paper. Storing digital data is both hard and error prone, and it also requires them to have the technology and power to read it. If things really go to hell, this isn't a guarantee. Paper ensures they can at least view it no matter what. It'll degrade eventually, but it'll hold up better than digital.

Any thoughts on tape? Lto tape is designed for 10+ years

so, I would suggest talking with an archivist. Many libraries will have archivists on the payroll (Or know one, anyways) and they'd likely be happy to talk about archival methods.

personally, what I would do- and I make no guarantees that it will work for a decade- is to seal the hard drive (or whatever media,) inside a vacuum bag with a shitload of silica desiccant gel. maybe double bag it with even more silica gel, then place it inside a pelican case. if you double bag, splurge on the indicator stuff and let it sit for a week.

but I'm not an archivist, and they may laugh at my suggestion.

Ammo can with silica gel beads.

Drop a thumb stick (mechanical failure) into a plastic zip-lock in a vacuum (oxygen) then into a metal thermos mug with water (pressure and radiation) then dig it really deep (accidential discovery and weather). By the time it deteriorates you'd have problems finding USB interfaces to plug it in. The location itself is largely irrelevant, but I'd recommend some place far from human-occupied places.

The authoritarian state problem isn't solveable, but you can defend it by obscurity, like not leaving a trace of thinking about this info cache, or leaving too many of these caches to reliably dig up all of them.