Setting up your new Mac with Time Machine
The first thing you'll need to do is buy an external hard drive. Apple recommends that you use a hard drive that is approximately two to three times the amount of data you're going to be backing up. That's a rule of thumb, not a hard and fast rule. Here at TUAW, our recommendation is "buy the biggest drive you can afford."
Let's say, as an example, that you're going to be backing up data on a new 11" MacBook Air that has a
160 128 GB SSD built in. Multiply that number by two or three, and you get a range of 320 to 480 GB. A quick look at OWC's website and Amazon shows USB bus-powered portable drives ranging from around $50 for the 320 GB drives up to $80 or so for 500 GB drives. If you can afford it, go with a 1 TB or larger drive.
Once you have the hard drive available, connect it to your new Mac via USB, FireWire, or eSATA -- whatever connection both the drive and your Mac share. For the MacBook Air, it's going to be USB 2.0, since that's the only external port available. The Mac will recognize the drive and mount it (make it available for use). If the drive is formatted for Windows, you might want to use the Mac Disk Utility (found in the Utilities folder, which you can pull up by selecting Utilities from the Finder Go menu, or just look in your Applications folder) to erase the drive and format it as Mac OS Extended (journaled).
If the drive is in a format that the Mac recognizes, it will ask you if you want to use the drive to back up with Time Machine:
Click "Use as Backup Disk," and Time Machine begins to back up your Mac (see below). Note that the first backup is going to take a while. Subsequent backups take a lot less time, as only changes to your Mac are being backed up.
How often should you back up your Mac? If you have a desktop machine and the drive is connected to your Mac permanently, then backups are going to happen every hour by default. With Macs that aren't always connected to their backup drives, Time Machine backups will only occur when the drive is physically connected. For my MacBook Air, for example, I try to remember to plug in the backup drive once a week. That means that I could lose up to a week or so of work, but since I save all of my important work "in the cloud" to Dropbox, I'm not as concerned about not having an updated backup. My iMac is a different matter, and it is permanently attached to a large drive array for continuous backups.
I'll be writing another Mac 101 post soon on how to restore files or a complete machine from Time Machine backups, so be sure to keep your eyes open for that one.
Send in the clones: Creating a bootable clone of your Mac
One of the negatives of using Time Machine is that the backups are not bootable. What does that mean? It means that if your main hard drive destroys itself, you can't just boot from that Time Machine hard drive. Instead, you need to replace the hard drive, install Mac OS X on it (and usually you want to install all of the OS X software updates before you get started with your file restore), and then restore your data. That can take a while, and for people who rely on their Macs for business that can be quite annoying.
A good way to get up and running again quickly is to create a bootable clone of your Mac's hard drive. There are two Mac apps that are really good for doing this: SuperDuper! ($27.95) from Shirt Pocket Software, and Carbon Copy Cloner (free, donation requested) from Bombich Software.
Both of these applications are well-suited for making bootable clones, and many long-time Mac users prefer using either of the apps to do their everyday backups instead of using Time Machine. Having that bootable clone can really come in handy when your primary drive dies and you need to get up and running immediately. You just reboot the Mac, pressing the Option key while you're doing so, and select the clone drive. It boots, and you're in business.
The "perfect backup" combines this bootable clone with your Time Machine backup. To do this, you want to start with an empty drive, use either of the tools described here to create the clone, and then use Time Machine to store your backups on the same drive. In this situation, you have the bootable drive plus the ease of use of Time Machine.
Off-site backups are good insurance
One problem with backing up a computer to an external hard drive is that if your home or business is damaged by fire or flood, chances are that both your Mac and your backup are going to be destroyed. Some people will swap out backup drives every week or so, taking one drive off site while keeping one for backups. Another idea is to buy a fireproof / waterproof drive from ioSafe. These drives protect data from fires at temperatures up to 1550°F for a half-hour and immersion in water 10 feet deep for up to three days.
My choice of an off-site backup is through an online service called Backblaze. For $50 a year, Backblaze will back up as much data as I can send 'em. Any time a file is changed or created, that information is encrypted and sent to Backblaze. Backblaze is similar to Time Machine in that you can look at previous copies of your backup data to recover individual files.
With this service, the first backup is going to be quite slow -- don't be surprised if it takes days or weeks if you have a lot of data on your Mac. After that time, you can just forget about it. Whenever your computer is connected to the internet, it's being backed up.
If your home is destroyed by some disaster, you don't want to wait for weeks to get your data back. The Backblaze people will copy your data to a disk drive and ship it to you.
Similar services include Carbonite for Mac ($55 per year, includes free iOS apps for accessing your data from anywhere), and Mozy Home ($55 per year). If you just want to back up critical files, consider using Dropbox. It's free for up to 2 GB of files, $10 a month for 50 GB, and $20 a month for 100 GB.
Whatever you do, back up your Mac
In this post I've given you some options and ideas about doing backups. Time Machine makes backing up your Mac a piece of cake, and if you want to get even more security and piece of mind, you can create a bootable clone of your Mac and/or use an off-site backup service. The important thing is to start backing up your Mac now, not after your hard drive fails. If you have any ideas or questions about backups, leave them in comments below.