Q: I have a bunch of applications on my iPhone 3G. My iPhone backup folder on my computer is now 3.4 GB. It has 8 files ranging from about 350 to 700 megs created over the last month since I got the phone. Is there anyway to reduce this file size or can the older files be deleted? I use a Macbook Air with the SSD, which has a rather small hard drive.
A: In this case it would appear that you have additional backups for your iPhone that iTunes is still keeping around. As of iTunes 7.7, an additional backup of your iPhone is retained each time you do a full restore or update the firmware on your iPhone. With four firmware versions released since the original iPhone 3G release, this means that you likely have at least four backups lying around that you may no longer require.
You can see the list of backups that iTunes is storing by selecting the Devices tab in your iTunes 8 preferences (this tab called Syncing in iTunes 7.x):
The date and time each backup was taken is shown, and the backup with the same name as your device is the most current one. Other backups will have the date and time that they were saved appended to the end of the device name.
If your iPhone has been working fine and these backups are more than a couple of days old, you most likely do not require them. You can remove them simply by highlighting the backup in question and clicking the “Delete Backup” button (iTunes 8) or “Remove Backup” button (iTunes 7). The backup folder and files for any backups you remove will be deleted from your computer as soon as you hit the OK button.
You should also consider upgrading to the latest iPhone v2.1 OS, as this now backs up only data from your iPhone, and does not store redundant copies of the applications themselves. This should resulting in significantly smaller backups—in our testing our largest backups shrunk from 565 MB down to 32 MB after applying the iPhone v2.1 firmware, and ran significantly faster as well. Be sure to check out our Instant Expert: Secrets and Features of iPhone 2.1 for more information.