It may not be the most versatile or powerful backup solution, but itís a beautiful thing to be able to just plug in an external hard drive and let Apple do the work. I have a dedicated drive sitting on my desk at work backing up my MacBook Pro throughout the day and acting as an off-site backup when Iím home. Itís a very reassuring tool.
But is there anything you can do as a user to customize your backup settings or manage your data more flexibly? It may not be immediately apparent, but there are a few great opportunities to make Time Machine work smarter for you. Read on for my thoughts.
Cut The Fat from your Backups
The nature of Time Machine is to back up everything on your system drive. For some, this fits the bill perfectly. But there are many large files on your Mac youíve probably never used and may never use at all. Itís wasteful to back these up, especially if youíre working with a space-restricted external drive. Letís look at where some of these files may be hiding and how to remove them from your backups.
Thereís a sizable folder full of Garageband resources (loops etc) on the hard drive of ever iLife user, which is not likely something youíll miss if your hard drive ever crashes out. Even if you do, itís easy to replace from the iLife installation disc.
To exclude this or any other data from your backups, click on the Time Machine icon in your menu bar and click Open Time Machine Preferences (or open the same preference pane directly from Apple Menu > System Preferences). Click Options:
To add an exclusion to the Options screen, click the Ď+í icon and browse to the location of the folder or file. For the Garageband data weíre after, browse to Macintosh HD > Library > Application Support > Garageband and click Exclude. You can continue to build this exclusions list as long as you like, saving valuable gigabytes from your backups. Letís look at some other common offenders and options.
If youíre feeling particularly ruthless, you can exclude your entire System folder from backups. This will of course make it impossible to use Time Machine for a full system restore in the event of a complete hard drive failure, but none of your important personal files are stored here, so this can be a wise exclusion if personal data is all youíre trying to protect. You can always reinstall your operating system from disc in cases like this.
Using the same method as described above, exclude the System folder by browsing to Macintosh HD > System folder from the Options screen.
Note that Snow Leopard is very lean for a modern operating system, so this folder is only 2.5GB in size. Personally, I keep this backed up just in case one day I have a hard drive failure and donít have the time to go through a full OS reinstall from disc.
The Heavy Movers
There are also some folders on your hard drive which see a lot of constant traffic which you may have no need to back up. These can be the biggest offenders in Time Machine wastage. The Downloads folder is a perfect example of this. If youíre a frequent downloader of movies, TV shows, music or any other large files, backing up the Downloads folder will fill your Time Machine drive to capacity in no time at all. This is a perfect candidate for exclusion.
Another is the Podcasts directory in your iTunes library (only for those who listen to podcasts, of course). Iím a heavy podcasts listener and despite having most podcasts set to delete anything older than the last 10 episodes in iTunes, my Podcasts folder is sitting pretty at 9.8GB currently. Again, files are constantly being added an removed as new episodes arrive, so this is a perfect folder for exclusion. Add the directory User > Music > iTunes > Podcasts to your exclusions list.
Remove All Old Instances of Unwanted Files
Of course, all these exclusions are well and good for preventing future backups of the selected files, but what about the backups that Time Machine has already performed? Is there any way to reclaim this space?
Easily, fortunately. Open Time Machine and locate the most recent backup which included the file or folder youíre trying to remove. With the file/folder selected, click the Action menu (gear icon) and choose ĎDelete All Backups of (filename)í:
Find Hidden Offenders with DaisyDisk
You may have many other large files or folders hiding away on our hard drive you have no need to back up, but it can be hard to know where to look for these without a little help. Luckily, there are some great utilities available to help you track down the files and folders which are consuming your hard driveís space.
One such tool is DaisyDisk. Itís very visual and easy to use and makes it almost fun to track down these files. You simply select the volume you want to scan and give it some time to work out directory structure and disk usage, then drill down through the offending parent folders (which will show you the size of their contents in a handy colour-coded graphical chart to find the offending files).
If you donít feel like coughing up any cash for a tool like this (DaisyDisk is $19.95), the Omni group have a similar tool called OmniDiskSweeper which comes free of charge. It doesnít have the speed or great interface of DaisyDisk, but it can give you the same information without too much extra hassle.
Change Backup Interval
If Time Machineís hourly backups are either too frequent or not frequent enough for your taste, you can change the setting if you know where to look. Its nature as a zero-config tool makes this unavailable in any of Time Machineís menus or preferences, but if you navigate in Finder to Macintosh HD > System > Library > LaunchDaemons youíll find a file called com.apple.backupd-auto.plist. This file contains a parameter for the distance between backups in seconds (3600 by default; 1 hour):
You can freely change this setting and re-save the file to change the interval for future backups.
Do a Complete System Restore
Time Machine is primarily intended for easy retrieval and restoration of individual files or folders from any point in time, but it can also be used to restore your entire mac in the event of total hard drive failure.
After repairing or replace the hard drive, follow the steps below:
- Plug in the Time Machine backup drive. Insert the Snow Leopard installation disc and double-click the Install Mac OS X icon.
- At the Welcome screen, rather than proceeding with a new installation of Snow Leopard on the new drive, click Utilities > Restore System from Backup. When the Restore Your System dialog appears, click Continue.
- Choose your Time Machine backup disk. Naturally, choose the most recent backup. The installer will now copy everything from this backup to your new hard drive.
- After this is complete, your hard drive will be restored to the exact state it was in before your HD failure. You're back on your feet!