QUESTION :
I wanted to install Windows on a MacBook Air using bootcamp and hence create a second partition. The problem is that it only has a 64 GB SSD disk and my MacOS X installation takes up 21 GB. Is that normal? Is there any way to reduce the size of the original install without erasing it?
ANSWER :
Considering that hard drives today come in the terabyte range for entry-level home systems, yes, I’d say that 21 gig is small potatoes. One of the tradeoffs with SSD’s today is capacity; you get blazing speed but lower capacity, unless you want to pay a LOT more money.
As time goes by, SSD’s will get less costly and more capacity.
As for the size of your installation, are you talking about JUST OSX? Or your entire partition? Because only you can answer if you need what you have installed. Use a tool like Disk Inventory X to see what is taking up your disk space.
As for your question of reducing disk use, you can either find a compression program for OS X (which I’d not recommend) to crunch space, or you can delete things you know you don’t need and be vigilant in your application data caching/storage/program installations. But with only 64 gig of space, you’re going to be cramped with two operating systems on the drive.
If you really need Windows and OS X for your work, I’d suggest a trip to the Apple Store and get a larger SSD drive or buy a decent one online and do the work yourself if you don’t have Applecare. You’ll be glad to have the extra space rather than trying to shoehorn it in.
Download OmniDiskSweeper and run it on your system drive. This will help you identify how your storage is laid out and which directories are consuming the most space.