Time Machine is great for keeping a local backup of your system, but if you're rather not worry about having a physical drive plugged in all the time you might want to consider an online solution instead.  There are plenty of over-the-air (OTA) backup solutions, though not all are very affordable for a small smattering of system files. Fortunately, there are services like CrashPlan, which offers free back up to multiple place. Read on, and we'll show you how to set it all up. 

What You’ll Need

>> CrashPlan (Free Onsite backup tool)
>> Extra Mac with free drive space

About CrashPlan

CrashPlan is a tool that allows you to backup to CrashPlan’s servers remotely, but the application can also be used to backup your Mac to another Mac or over the air through your local network or over the web.

1. Setting up the Client

First, lets set up the client machine (the machine that will be backed up to the server). To begin, launch the Installer that you downloaded from the CrashPlan website. Complete the installer, and then launch the CrashPlan application from the Applications folder on your Mac.

In the Settings > General tab, specify a name for your computer. Be sure to click “Save” button at the bottom of the window, and leave the application running as we will revisit it after we set up the server.

2. Setting up the Server

Now it’s time to set up the machine that will store the backup from your machine. You’ll want to make sure that the server has enough free drive space to store your entire user directory.

After installing CrashPlan on the server, navigate to CrashPlan > Settings > General, and click the “Enable” button for “Inbound backup from other computers.” In the pop up window, ensure that the “Accept inbound backups” checkbox is checked. Click the folder icon in the “Default backup archive location” section to set the location of where the backups will be stored on the server.

Once you’re finished configuring the settings, click the OK button, and then Save the changes.

3. Backup the Your Computer

To set up the client backups, click Destinations in CrashPlan on the client machine, and then select the “Computers” tab. Select the Mac that you just set up as a server from the “Your computers” list, and then click on the “Start Backup” button.

CrashPlan will immediately go to work, backing up your user’s folder on your client Mac. You can see the status of the backup process from within the CrashPlan application, or you can also view the status from the CrashPlan menu bar item.

Cory Bohon is a freelance technology writer, indie Mac and iOS developer, and amateur photographer. Follow this article's author, Cory Bohon on Twitter.