Syncing Does not a Backup Make

Syncing data to the Internet (“the cloud”) is all the rage these days and with the coming of the iPad, we’ll surely see more of it. Whether you are using MobileMe, Dropbox, or any one of the variety of other syncing programs, you may be one of the increasing number of people using these services to backup their data.

The problem, though, is that syncing is not backing up.

Syncing’s main focus is making sure your data is accessible and identical at multiple locations. If you have a disaster at one of these locations, a syncing service will make sure you still have access to your stuff. That’s handy and is seen by people as a way of backing up. Lose your iPhone and your contacts are accessible via the web. Sync to Dropbox and if your MacBook hard drive dies, you can access your synced files via the web or another computer.

Unfortunately, syncing operates under the age-old computer principle of Garbage In Garbage Out. When syncing is working properly, a change made on one device is propagated to the web and to all other devices. If that change was unintended, the service might have a previous revision, but don’t count on it. A problem with data on one device is copied to all other devices in your sync scheme.

When it’s not working properly, stand back because things get ugly. I was a recent victim of this. I’ll be polite and won’t mention the name of the service, but it wasn’t a “sweet” experience. Somehow this company’s database was corrupt for my account and instead of syncing changes I made on my Mac to my PC, the server decided I had deleted a critical folder. I literally watched as the software started deleting folders from my Mac without warning or confirmation. I immediately unplugged my Internet connection to minimize the damage. While only the fates of the cloud know what really happened, the post-mortem analysis I had with their engineers indicated my PC’s sync database somehow “thought” I no longer had a folder on my hard drive and then told the cloud to delete it from other computers. Blame it on a PC to mess up a Mac. Of course, their server didn’t have a backup. A two-fisted punch right to the gut.

These same concerns also hold true for your calendars and contacts from MobileMe. Even though you sync them to the cloud, you should still perform a local backup of your Address Book and iCal. Don’t be lulled by the siren of the cloud assuring you that your data is safe. The cloud is a jealous mistress who can swipe data right from your hard drive. Being old school, I don’t fully trust syncing or the cloud and so I fully backup my hard drive via Time Machine and dedicated online backup services. While my sour experience was annoying, I was able to quickly recover.

Others have not been so lucky. Account and database corruption are a fact of computing and because syncing doesn’t only copy data, but remove it, it’s not a backup solution. A true backup solution cannot remove data from your drive, only copy it. Whenever I read backup software reviews, commenters ask why synchronization services aren’t mentioned. Now you know why.

Don’t rely on services like MobileMe and Dropbox as a backup. Your data will thank you.