If, say, your entire office burns down due to an electrical fire from a photocopier next door, off-site backups are worth their weight in platinum. If you don’t believe me, just look up how much professional data recovery services cost and compare that to the weight of a hard drive or fifty. Some people use e-mail as a back-up system, but it isn’t really appealing as a long-term, scalable solution. Amazon’s S3 provides variable pricing and is scalable, but may be overly complicated for backing up small amounts of data. Some off-site back-up services such as Backblaze are great deals for people with large storage needs ((I am not affiliated with or endorsing Backblaze. I just find their blog posts interesting.)).
From a monetary standpoint, an off-site back-up service can get to be rather expensive (although Backblaze is a trail blazer). But just think about all those datacentres running and consuming energy to keep your data safe for the occasional data push and, hopefully, the very rare data retrieval. In the meantime, you’re paying these services to keep a hard drive around (and maintain an Internet connection) — something you’d be willing to do yourself, if only it afforded the same protection as an off-site backup.
Enter distributed back-ups. Transfer your data, encrypted, to a trusted person at some predetermined interval and they can do like-wise onto your computer. You could do it with an untrusted person, although they might be more likely to hold your data hostage (there’s a way around that, though). There’s no need to keep these computers up and running all the time or to pay a monthly fee. Just make sure that person lives far enough away so that, in case of a zombie epidemic, you can still retrieve your data, assuming you haven’t also become a zombie ((In case of zombie pandemic, you’re in deep doo-doo, regardless of where you store your data)). Jon Pipitone tells me that an open distributed back-up system exists. I’m not sure how well it meets my data integrity and availability (or lack-thereof) requirements, but it seems like an interesting start. I’d like to start an open source project to make distributed back-up systems accessible to “typical” users, possibly building on DIBS. If anyone is interested in using or developing such an application, drop me a line either through e-mail or via this blog.
Online backups are a must, and Backblaze does a great job at them. For Mac users, it’s the service I recommend (read my Backblaze review). Mozy is another great solution for online backups. Each costs about $5 / month, which won’t break the bank. Like you said, S3 can get pricey, and it’s not very easy to understand just how much you’ll end up paying, until the bill comes.
I haven’t looked at distributed back-ups too much, only because I don’t think there’s anyone I know who would keep the data for me, and give me the connection speeds I’d like. However, if a bunch of your friends are game, you can easily (and cheaply) get 2-3 backups going.