erase disk and reinstall mac os x yosemite

problem

can not turn off filevault

$ diskutil cs list

1. check status
$ fdesetup status

2. enable filevault
$ sudo fdesetup enable

3. disable filevault
$ sudo fdesetup disable

solution

i do want a fresh start!!!

erase all data

reinstall mac os x yosemite

1. backup your essential files

2. connect to the internet

3. restart you computer

   • then hold command+r keys while the computer restart

4. choose disk utility and then continue

5. right click your startup disk

6. unlock your startup disk

7. click erase tab

   • choose mac os extended(journaled) format

   • type a name for your disk

   • click erase

8. after erased quit disk utility

9. choose reinstall mac os x click continue

10. follow the instructions