If you’ve ever lost data due to a crashing hard drive, an oops when hitting the wrong key, or due to someone else’s negligence, you know that backups are serious business. If this has not happened to you, rest assured that it is a severe pain when it does happen. Chances are that, at least once, it will happen to you. And when that data happens to be digital photos, an extensive music collection, work documents or your draft novel, you will regret not having a backup system in place. Don’t wait for it to happen. Take it from someone who lost two months worth of work years ago and has had redundant backups ever since.

There are a number of different backup options available for the Mac – some good, some great, and some that are just awful. One of the problems with backups is the inconvenience factor: swapping tapes, turning on external drives, even just remembering to run the backup software. Fortunately, with online backup services and other intelligent behind-the-scenes programs available, backing up can be something you do without even thinking about it.

While one of my favourite applications is DropBox, which you can use to sync files between multiple computers, it doesn’t really lend itself well to backups. Other solutions exist that are far more efficient. One such service is CrashPlan.

CrashPlan is nice and easy and, for the budget-conscious, it can be used for free. The CrashPlan+ plan offers some nice extras for a competitive price (such as backing up to their servers), but if you have extra storage or extra computers, or even friends that also use CrashPlan, you can certainly use the free service and enjoy reliable, redundant backups. It is a java application, so it’s cross-platform, meaning that I can back up my Mac to my Fedora workstation and to a friend’s Windows system, if I so desired.

To begin, you need to sign up for a CrashPlan account, regardless of whether you use the free version or not. This allows you to link different computers together and receive email notifications of when backups are done or if they fail.

When installing on the Mac, you can opt to have CrashPlan run as the root user or as the user installing it. If you don’t plan to back up other user’s files (such as on a system with only one user account), to reduce risk, I would install as a regular user. To do this, select “Customize” when the installer is ready to install and select “Run Backup Engine as User.”

Once it is installed, CrashPlan will start. By default it will back up your entire home directory, so if you don’t want every file in your home directory backed up, on the Backup pane of the application, scroll down to the Files selection and click the Change button. Here you can also select files from other volumes or directories that are outside of your home directory, that you want to backup.

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The Destinations pane is where you define locations for where backups are to go. You can use a friend code here to backup to a friend’s computer, select another computer on the local network (only those that have CrashPlan installed will be available to select from), select local folders (which can also be directories mounted via SMB or AFP), and online storage (CrashPlan Central, which you do need to pay for).

The Restore pane is where you can find files to restore. So if you have accidentally deleted a directory that is backed up, you can restore it from here. You can also restore files from other computers whose backups you store. If the backup is encrypted, you will need to provide the password prior to being able to view what files can be restored.

The Settings pane is where you can define particular options for CrashPlan, such as where on your system you will store backups for other computers (in the General tab). You can also determine how much CPU CrashPlan is permitted to use when you are away (and you can define the period of inactivity to consider being away) and when you are not. You can define what alerts you receive and where, either via email or Twitter. In the Backup tab, you can configure advanced settings like whether or not to enable encryption and compression, you can use regular expressions to exclude certain files (this is a very nice touch), and when the backups will run. In the Network tab, you can limit how much bandwidth is used for backups and in the Security tab, you can set a password to the encrypted backup: either your account password or something entirely different.

CrashPlan is easy to use. Upon installation, I mounted a remote SMB folder for my little NAS box and defined a local folder backup on it. Then I installed it on my Fedora workstation and enabled two-way backups to it: backing it up to the Mac, and vice versa. The initial backup took some time due to the large amount of data being backed up. The remaining time counter is quite inaccurate, so take it with a grain of salt. Backing up 47.5GB at one point to the NAS box, CrashPlan told me it would take 2.5 days. Subsequent backups are very fast, as only changed files are sent.

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If you are concerned about storing your backups in the cloud, CrashPlan offers a great alternative. You can store backups exclusively on machines that you have control over, without transmitting any backup data to the CrashPlan servers. And if you want to take advantage of CrashPlan+’s extra features and want to store your data in the cloud, encrypting the backup with a password other than your login password will ensure your privacy (as will the 448-bit Blowfish key length used for file encryption available with CrashPlan+; CrashPlan’s free offering only provides 128-bit Blowfish key lengths).

All told, it’s hard not to recommend CrashPlan. It fits the budget of many people, and will also appease those with stringent security or privacy concerns by keeping their backups on trusted systems.