Components for Building Computers From Scratch/Future of permanent storage
I backup my computer (at least my files that aren't OS related) with portable hard drives through USB and was wondering if a 100GB optic disc or some durable write once medium is on the horizon? I am worried about the portable hard drives eventually getting old and unreadable and since they're magnetic tape they start to degrade sooner and of course aren't safe around magnets. Any knowledge of things coming up?
All storage media will degrade and fail eventually - a good back-up plan also includes media maintenance, and should rely on multiple copies of the same data that are regularly checked and transferred to new media. In addition to hard-drives, there are a number of large-capacity removable media solutions like Blu-ray ROM that can achieve the storage you want - BDXL supports up to 128GB per disc, although the discs are relatively expensive (to the point that it is probably cheaper to burn multiple BDR or DL DVDR volumes). You could also look into M-DISC, which is designed to have better longevity than conventional Blu-ray or DVD media, however as far as I am aware there is not currently a defined BDXL M-DISC standard.
I also wanted to point out - hard-drives do not use magnetic tape. They are either solid-state or platter based. Tape is certainly a viable storage media for offline data, although the initial investment can be fairly high. Archival quality tape does exist in very large capacities though, into the many hundreds of GB. The danger of magnets around hard-drives is perhaps overstated by many sources as well. Certainly you wouldn't want to expose them to an MRI, but they aren't damaged by the magnets found inside of your computer, nor from being ganged together in the same cage. They have very powerful magnets inside of them, and the magnetic force required to actually modify the platter is substantial. Especially through the external casing. What's most likely to fail on a hard-drive is not the platter, but the mechanical components that actually make the drive work. With a USB or otherwise external drive, the controller board can also become a point of failure as well. Generally a few years is a good life-cycle for a hard-drive, and replacing your back-up media that often is not a bad practice to get into. Of course if the "old" media still works, keep it around - more copies is never bad when it comes to back-ups.
Overall the "best practice" for important back-ups would be to have both hard-drive and offline media copies stored locally and off-site. If the data is exceptionally important, consider a secure storage facility like Iron Mountain. Cloud storage may also be an option, depending on the nature of the data (some types of data cannot be legally stored on cloud services). In practice though, the easiest solution would be to burn a new disc every so often, as well as keeping one or two hard-drive copies. Then duplicate the discs, and keep a copy in a safety deposit box, or at a friend or family member's house (even better if you can send it somewhere out of your region of the world). The protection here is to prevent against loss due to fire, flooding, and so forth, as opposed to data-loss due to hardware failure or accidental deletion. The level of investment just depends on how important the data is.