Chosen Solution
Macbok Air 13" Mid 2012 Repair Whenever I put my system on it takes time to boot, usually shows the beach ball repeatedly for long when in the middle of operations. I don’t know what might be the cause, I need help.
With SSD’s free space is also needed so the drive evenly wears. At this point I would recommend you create a bootable USB thumb drive so you can boot up under it to run Disk Utility - Disk First Aid. Let’s see what it tells us. If you still have Mavericks run repair permissions and then repair disk.
In addition to running to using the Disk Utility (which you can also run in recovery mode - hold down Command + R when powering on and wait until you see the Apple logo before releasing the keys) I wouls also suggest doing a PRAM reset as the the System Manager table may be a little corrupted. To do this, press the Option-Command-P-R and Power button and hold until you hear the boot fanfare 3 time and then release all the keys. Your MBA will rediscover the hardware and create a new boot table.