Free up space without getting into the OS

If you have another Mac and a Thunderbolt cable to connect the two together, you can boot your mother's Macbook Air in Target Disk Mode.

http://support.apple.com/kb/PH10725

This way, you can access the drive of the MBA on the other Mac, just like an external drive, without having to remove it. Then you can clean up your files and when you're done, eject the drive front he other mac and reboot the MBA as normal.

 

I recommend starting from an external HDD and saving the files you need and then reformatting the internal drive. Also, if you feel your Mum's SSD is to small you can replace it:

http://forums.macrumors.com/showthread.php?t=1729071

http://www.amazon.com/Transcend-Jet...06529&sr=8-7-spell&keywords=transend+jetdrive

And with this method your old drive goes into an enclosure to be reused as an external USB 3.0 drive.

I put one in my 2012 MBA.

Most experts seem to agree that SSDs shouldn't be filled to more than 75% of capacity, but my rule of thumb is between 60 to 70%.

Lou

 

I use Carbon Copy Cloner to create bootable USB images of my internal, boot from the CCC image and mount the internal if I've got issues.

 

Have you actually done this? As far as I know, target disk mode is limited to FireWire & Thunderbolt.

 

^^^^YOU ARE INDEED CORRECT!!!! Sorry for leading the OP astray.

Lou

 

I re-read the original post, and you're unable to boot the system?

 

The very first sentence covered that.