I’d been wondering about online backups recently. My current backup system involves a complete hard drive replication onto an external drive. This is fine for your average HD crash, but if the flat is burgled / catches fire I’m screwed. Sending a copy of all files to some server in a fire-controlled room in the USA has always seemed like a good idea, but the sheer amount of data involved has always made it seem impossible. I have ~100GB on my hard drive, and at 256k upload speeds, this would take around 60 days to transfer. Even if I cut this down to just photos etc, that’s still a major amount of data. Last time I really looked at online backups was a year ago, and there wasn’t anything that could

This year things are different. My emails are all stored on Gmail. Assuming Google don’t go under, I can be pretty sure that’s safe. All my music is backed up onto my iPod, which is almost always with me. The iPod also has reduced-res versions of all my photographs, and high-res versions of all the best are stored on Flickr. If the worst happens then I don’t mind being stuck with smaller versions of my photos, so that’s 50gb of data I don’t have to worry about backing up remotely. So what’s left that I’d be upset to lose?

• Pre-Gmail emails
• Business documents, letters, invoices etc.
• Outlook calendar and contacts data
• The occasional short story or other creation
• Microsoft Money financial data

I realised that they take up very little space, so I could start thinking about the data it would be a shame to lose, which include:

• Strange little short films I’ve made over the years
• Personal documents from the last fifteen years, including random notes, ideas, letters and large amounts of school and coursework.
• Settings files for various applications that require large amounts of configuration
• Save games from computer games

Of the above, the short films are all that need some processing for online backup. The uncompressed files are much too large, but I’m happy with an mpeg or similar. The total amount of data was small enough to make online storage feasible, so I started looking for the best solution.

There were various options¹, and most of them involved a small monthly fee for x amount of space and bandwidth transfer. I was happy with this - $10 a month is more than reasonable for that kind of service, I think. I’d have to set up an automatic backup to happen overnight one day a week, or something. It would take a while, and would eat into my monthly broadband bandwidth allowance. Hmmm, this was going to be a fair bit of work to get set up smoothly.

Enter Mozy.

Mozy have recently started offering their services as an online backup system. They differ from other services in that they’re tailored for backups rather than remote storage and access. They provide you with a small program which performs one full backup, and from then runs in the background and compares remote and local files, only uploading those which have changed - a differential backup. This saves vastly on both time and bandwidth for me, since much of my data is static.

The deal is that you get 1gb of space for free, in return for advertising emails from their sponsors. This can be upped to 2gb if you provide more personalised information. You’re also only allowed 4 ‘restores’ per month, presumably because they don’t want to be used as an online file repository.

I set up an account on Monday, downloaded the software, and set about configuring it. After scanning your drive for likely files you’ll want to include, the first question it asks is whether you’d like Mozy to secure your data with their own 448-bit encryption key, or whether you’d like to set your own key. In the latter case you are warned that if you forget this key you’re ‘hosed’, which made me smile. I chose to use my own key. I then selected the folders and files which immediately sprang to mind, set the backup to happen automatically when the computer isn’t being used (you can configure a specific time and schedule, if you like), and went to bed.

Unfortunately, the backup hit a snag 200mb into the transfer and stopped. I don’t know whether this was just a communications blip or something else, but I started it going again before I went out for the day. When I returned 540mb of data had been transferred (it must compress it before transfer, I guess) and Mozy was happily displaying its ‘backup complete’ message. Since then I’ve run it a couple of times, with transfers of 20mb or so, much of which is my iTunes music library XML file, which changes on a daily basis.

I’m impressed with both the software and the idea behind it. The main issue, I suppose, is whether I can trust Mozy. Who’s to say that they’re not lying about encrypting the data, and will sell it on to whoever they like if they run out of money? I tend to think that’s just paranoia talking. There’s no less reason to trust them than any of the other online storage companies, and various satisfied customers of Mozy can be found by googling. What happens if they go under? Well, my data will be sitting on a hard drive somewhere. Again, the chances of this data then falling into the hands of somebody who would use it for underhand schemes are remote. I imagine privacy nutjobs will stay well clear, but personally I see no other choice than to take this (imho, very small) risk, in return for the peace of mind of having my data backed up.

I haven’t yet had any advertising emails, and these are related to my only other worry: that their business model is open to abuse. If I wanted I could easily filter out any emails from Mozy and not bother looking at them. I won’t do that, as I don’t think that’s fair. I think it’s unlikely they’ll tempt me to buy anything, but Mozy are providing me with a free service and I’m happy to spend thirty seconds looking at an email in return for it. I imagine there’ll be a fair number of people, however, who will set up a filter and not bother. For this reason I’d actually be happier to pay for the service, and if they set up some kind of non-advertising but $5/month option I’d happily switch over to that, if it helped ensure their continued existence! But maybe that’s just unwarranted skepticism on my part.

Any other problems? Well, their software took a good few minutes to scan for files and I had to wait for it to finish before I could start configuring; it would be nice to have the option of skipping this, since I selected all my files manually anyway. I’ve had a couple of dropouts during large transfers and then had to restart manually, so a ‘retry after x minutes on fail’ would be helpful. Also, the display of how much data remains to be uploaded isn’t clear, and the time remaining is a little temperamental. The software is in beta, however, so I’m sure this is the kind of thing they’re looking at.

All in all, I’m impressed.

1. There’s a comprehensive review of online storage providers here, although without any focus on backup particularly. [↩]