B2 is an upgrade option. You can still store an unlimited amount on their standard plan, or upgrade for a little bit more for access to a year's worth of changes. It would be worth it to keep a separate desktop with a dozen drives connected and pay for a second annual subscription if you have that much data.
The one-year retention plan adds $24/year. Even the "forever" retention plan for 50TB would only add $250/year.
If we're talking about home use, B2 really isn't necessary. And if you want a daily rotation every day for a year the tape costs can add up, depending on how much data Cha he's day to day. For home use, an HDD backup combined with something like Backblaze seems like a pretty reasonable cost for two layers of redundancy and a year's worth of file versions changes.
Kind of a hypothetical scenario for me—backing up 50TB to cloud would saturate my uplink for a full year and more. By comparison, it’s about four days of drive time on LTO-5. So while LTO-5 is a plausible way for me to store 50TB of data, cloud storage is decidedly a fantasy.
Personally—gonna say I don’t trust arrangements where I know the other side is losing money on the deal. This includes “unlimited” storage. I put “unlimited” in quotes because all of these other services with unlimited storage have, at some point, gotten shut down their unlimited storage plans. That’s why I compare to B2… not really interested in gambling on those things. So I would take B2 as the baseline for comparison when you're talking about this much data.
Amazon once had an unlimited storage option, if you recall. One data hoarder was recording cam girl streams and had just north of 1 PB in his Amazon Drive folder. Whole thing got shut down shortly after.
Bandwidth limitation is a great example of how specific circumstances should dictate backup protocol. Tape absolutely makes sense there even in a home environment. In your case, if it was really critical, I'd probably want to get two tapes at certain intervals so I could ship a copy off site and have the off-site copy online in a dedicated server at a data center so I could retrieve critical files if needed. Probably too extreme for a home setup unless it's a home business, but I've also had to restore from an overnight tape when a database went corrupt (multiple times) so if I was still involved in that sort of sys admin work I'd be a bit paranoid.
As for financial issues with "unlimited", Backblaze has a roughly 15 year track record and has been profitable for almost as long. They're not a typical startup looking to pump up a customer base by selling below costs and then dump to an exit acquisition or IPO. Storage is cheap, and they have managed to build a business that doesn't screw up the economics of low marginal costs by becoming overly bloated.
That said, they're still one of of two layers of redundancy I use for my home backups. I've seen cloud services lose files, so I'm banking on the fact that my own storage won't go down at the same time as two cloud services.
The one-year retention plan adds $24/year. Even the "forever" retention plan for 50TB would only add $250/year.
If we're talking about home use, B2 really isn't necessary. And if you want a daily rotation every day for a year the tape costs can add up, depending on how much data Cha he's day to day. For home use, an HDD backup combined with something like Backblaze seems like a pretty reasonable cost for two layers of redundancy and a year's worth of file versions changes.