Backing Up Your Data

If you're anything like me, you have an ever-growing appetite for hard disk space, and an ever-growing unease about how to keep all of that hard-acquired data from suddenly vanishing into the ether. The obvious answer is to back it up. But how?

In the old days (after floppies), CDs sufficed. But even with a modest accumulation of digital stuff, 700MB/disc didn't go very far. Then DVD burners became common, but even at 4GB (or 8GB) per disc, it takes a lot of discs, and time, to back up a typical collection of documents, photos, music, and video. On top of that, most burnable CDs and DVDs have a very limited and unpredictable lifespan. High-def DVDs aren't really ready for prime time, tape backup systems are probably most suitable for die-hards, and non-volatile storage devices (like USB flash drives) are still relatively small. So most discussions of hard disk backup focus on having another hard disk, or uploading data to a remote server.

These days, keeping your data safe requires more than a procedure; it requires a strategy. It's important to consider things like what portions of your data are most critical, how frequently various sets of data change, how private some of your data is (encrypt!), how long you need to keep it, and how much time and cost it's worth to keep it safe. Also consider the backup media characteristics: capacity, annualized cost per gigabyte, time and effort, ease of use, robustness, compatibility, and futureproofness. The most solid recommendation is to back up early, often, and to as many places as practical.

OK, you already keep essential data on your flash drive, back up some other key stuff regularly onto CDs or DVDs, and upload certain things to various remote servers. Maybe you even have the Firefox Gspace extension that lets you use your Gmail account as easy file storage. Let's focus on the high-capacity needs (but not forget about the inherent unpredictability of hard disk failures).

First, check out Lifehacker's articles on backups for Mac and for Windows

Don't have a spare drive? Space is cheap these days; the cost/gigabyte sweet spot is with the 300-400GB drives:


[Pricing data is for internal Seagate Barracuda 7200RPM 3.5" PATA hard disk drives from macsales.com as of 12 Apr 2007]

If you don't have a tower with a spare drive slot, add an enclosure, multiple disks, RAID, new controller, etc.; whatever it takes to put together a working subsystem.

Also, to get back to a time-based cost per gigabyte, let's be conservative and assume that you'll always have your data on at least two disks, and that you'll replace drives regularly at, say, halfway through the warranty cycle. So barebones ongoing cost would be ($0.28/GB)*(2 drives)/(2.5 years) = $0.22/GB-year, or about two cents per month for each gigabyte.

Expect to invest some time and effort into setting up hardware and software, backing up, checking backups, and periodically replacing drives. If you want to outsource all of that maintenance, and you're willing to pay for it ($0.20/GB transferred + $0.15/GB-month), you could go with something like the Amazon S3 service. It's a pretty safe bet that Amazon will still be around for the next generation. Windows users can also try Mozy (Mac version coming soon). For online backup, hopefully you have a fat upload pipe.

UPDATE (Apr 23): Mozy has hit the big time.

[photo credit: Wikimedia Commons]