In my opinion we are pretty well stuffed because there is no such thing as long term storage in this industry. 50 years is a pipe dream. 5 years is really stretching it. 2-3 years is likely. Tapes and discs (both optical and magnetic) all deteriorate. The only way to prevent data loss is to have a strict data management regime that will include documentation in case you should forget a step, and multiple on- and off-line and on- and off-site backups. But those individual back-up components need to be manged too.
Many of the posts to this thread have mentioned SATA drives. Well, consider this: what happened to PATA ? It's almost vanished in the space of a few months. SATA will go the same way one day. So will any media type. It's an inevitability of a commercially-oriented business world. The hardware and software manufacturers are looking after their interests; not mine, and not yours.
Even a well stocked SATA system with plenty of spare capacity will eventually need additional or replacement drives that will not fit or will not connect. Then you are up for another new system. Now that's a terrifying prospect because by then
you will not necessarily be able to copy your data from the old system to the new system. All of those SATA drives in the dedicated SATA storage system will be rendered useless as soon as the dedicated system controller itself dies, and then you find that a new one cannot be found, and your SATA drives won't fit the shiny new PC you have by then.
Similarly, in a years time none of your PCI cards will find a new home. None of your 16-bit system software will find an operating system. You might think "so what?" but the software we have for some of the older drives including tape is 16 bit. Even some of the 32-bit software died when Windows XP went to SP2, but of course other new software won't work without SP2. My favourite automatic backup utility no longer works and is no longer supported since Symantec bought out PowerQuest. Thank you Symantec, for nothing. There are just too many examples of this for us to believe it won't happen again.
Even the comfort of having a warranty is lost when the manufacturer has gone bust - warranties no longer apply.
I don't know what the solution is but I'm inclined to think that it needs to be low-tech and cheap and to have only just enough capacity for the short term. It also needs to be off-line most of the time to prevent runaway software from attacking it when it attackes the rest of your PC. [I had something try to corrupt all .jpg files on my PC despite having the latest AV and firewall facilities. It corresponded to installing Irfanview and went away when I uninstalled it, and yet zillions of people have used Irfanview without a problem. Lucky me, I guess, but I got the images back from my off-line backups. Careful me
]
Condider for example a pair of large-ish RAID 1 drives in a simple external controller so that...
(1) a separate PC and operating system is not required to drive it,
(2) if a drive dies you may be able to replace it,
(3) if the controller dies you may be able to replace that,
(4) if either the drive or the controller dies and cannot be replaced you can buy a whole new set of different technology or brand relatively cheaply
(5) when new technology comes out (such as SATA replacing PATA) you can buy a whole new set, with bigger capacity, before the old system has a chance to die,
(6) it is relatively affordable to replace it when required,
(7) with any luck it will still work when you upgrade to a new PC (and if it doesn't then there's time to replace it before you dispose of the old PC).
The longest-lasting image backups I've had to date are, believe it or not, on good old
film. What does that say for the digital photography/computer industry ?
The bottom line, in my opinion, is that
It is important that the backup solution must not be allowed to outlive the technology or the computer/software support or the manufacturer or even the manufacture, or else you will eventually find your backup is compromised, and it may happen much sooner than later.