It's not too early to start thinking about getting your Mac prepared for Mountain Lion. By the way, I'm going on record as saying that Mountain Lion will be released to the public on July 18, 2012 -- if history repeats itself, Apple will hold its third-quarter financial call on July 17th and announce the availability of Mountain Lion for the next day. [Well, that didn't quite happen -- but don't be surprised if it's still the day after the earnings call, now scheduled for 7/24. –Ed.]
One of the best ways to ensure a smooth transition to Mountain Lion is to make sure that you've cleaned your Mac. I'm not talking about washing and detailing your favorite Mac; instead, I mean getting rid of the junk files that accumulate from the first day that you pull a Mac out of a box and start using it.
First, it's a good idea to check your current disk usage to make sure that you'll have enough storage to perform the upgrade. Select Apple menu > About This Mac and then click the More Info button. This launches the System Information app. Click the Storage tab and you'll see detailed information about what's taking up space on all attached drives:
Expect Mountain Lion to take up about 8 to 10 GB of free space. If your drive is low on space, it's time to clean up. Free apps like Grand Perspective and Omni Disk Sweeper can tell you what big files are chewing up space, giving you an idea of what to delete. However, use caution! Don't delete files just because they're big. When in doubt, Google file names you don't recognize, and take special care removing files from your Mac's Library folders.
Also think about emptying the Trash. Some new Mac users don't realize that they have to empty it occasionally, so it can take up gigabytes of space. In Mail.app, select Mailbox > Erase Deleted Items > In all accounts to free up space. iPhoto also holds onto deleted photos in a special trash bin -- select iPhoto > Empty iPhoto Trash to move them to the real Trash, and then empty it again.
Another big space waster? iOS device backups. If you're now using iCloud backup to back up your camera roll, accounts, documents and settings, and you've been an iOS user for years, you might have a ton of backups chewing up space. To delete those backups, launch iTunes, then select iTunes > Preferences. Click on the Devices button, and you should see a list of device backups:
Select one or more of the backups, and then click the Delete Backup button to dump those backups and clear up space.
One more tip is to clean up temporary files and system logs. Your Mac normally runs UNIX maintenance scripts between 3:15 and 5:30 AM local time,
but if you have your machine shut off or asleep at night, they won't run. [As our commenters pointed out, while this used to be the case in earlier versions of OS X, modern versions will actually "catch up" on the maintenance routines when the machine is awake. –Ed.]
If you want to force a maintenance script to run, you can either install a free app like OnyX to perform cleanup and repair functions directly (a good idea), or use Terminal to run the scripts occasionally.
- Launch Terminal, which is in the Applications > Utilities folder
Type the following command at the prompt, followed by the Return key:
sudo periodic daily weekly monthly
- When prompted to type your Mac's admin password, do so and press return again.
As soon as the scripts have run, the Terminal prompt returns and you can quit Terminal.
Lastly, think about moving large folders or files to an external disk drive. The iPhoto and Aperture photo library and the iTunes Music folder are both notoriously huge.
These are some common-sense tips for clearing up space on any Mac, even if you're not going to be upgrading to Mountain Lion. However, an OS upgrade is a perfect time to change those hoarding habits.
For many new Mac owners, your move to Mountain Lion represents your first major upgrade. To help users prepare to make the jump, Steve Sande and Erica Sadun wrote Getting Ready for Mountain Lion, an Amazon/iBooks eBook. It's aimed at first-time upgraders and people looking for hints and tips about smoothing the transition. We're sharing some of our tips on TUAW in a series of posts about the 10.8 upgrade. OS X Mountain Lion 10.8 will be offered for sale in July 2012 for $19.99.