Mac OS X: Software Updates require more free disk space than update‘s size

This article has been archived and is no longer updated by Apple.

Installing a software update(s) may require more disk space than the total size of the update(s). If you do not have enough available disk space, you may see an alert message stating that you cannot install the update because you do not have enough disk space. This article applies to Mac OS X 10.2 and later.

You should always have enough free hard disk space on the Mac OS X startup volume. The exact amount needed depends on how the computer is used. Free space is used for virtual memory, iDisk (if you use .Mac), system and Internet cache files, and other temporary files.

When installing an update in Mac OS X 10.2 or later, disk space is needed for:

  • Downloading the compressed update
  • Decompressing the update without deleting the original download (the decompressed installation package is usually larger than the downloaded, compressed update)
  • Installing from the uncompressed source package
  • Any temporary files used during post-installation optimization

A downloaded update may be 50 MB large when downloading, for example, but may require 300 MB or more of free disk space to install. After installation (and restarting, if necessary), the temporary files should be deleted automatically if you're using Software Update.

Making more disk space available

To free up more space on the Mac OS X disk, or to effectively utilize what space you have, use these tips:

  • Empty the Trash (if you have multiple user accounts, log in to each and do this).
  • Restart the computer. If the computer has been in use for a while, restarting it may reduce temporary files that could be taking up space.
  • If you need to install more than one software update, install them one at a time.
  • Check your Applications folder for multiple versions of an application, and delete the earlier version if it's not needed (for example, you might have an iWork '06 and iWork '08 folder, but no longer need iWork '06). Note: You should not relocate Apple applications such as Safari, iTunes, or iPhoto from the Applications folder to a different location, software updates for Apple applications expect them to be in the Applications folder.
  • Back up large, non-essential files (such as ones on your desktop or in your Documents folder that you rarely use) to another volume and delete them from your Mac OS X volume.
  • Check your Shared folder (it's in the /Users/ folder) for any unnecessary files and delete them or back them up to a different disk.
  • Open QuickTime preferences, in System Preferences, click the Browser tab. If "Save movies in disk cache" is selected, click the Empty Download Cache button.
  • Empty your Web browser's cache. For example, in Safari, choose Empty Cache from the Safari menu.
  • Consider purchasing an additional or external hard drive, if your current hard drive capacity does not meet your needs.
Published Date: Feb 19, 2012