vi E37: No write since last change (add ! to override)

   When trying to quit vi, you present with vi E37: No write since last change (add ! to override) error message colored with red... What this vi error message trying to tell you that 'you have made some changes into the document... so you cannot quit just like that'...

DEVICE="em1p1"
ONBOOT="yes"
NM_CONTROLLED="yes"
TYPE=Ethernet
BOOTPROTO=none
E37: No write since last change (add ! to override)

That what vi try to tell... so we have two options... want to exit and save changes made to the document or just exit vi editor without making any changes to the document....

Vi save and exit
1.  Hit 'Esc' key twice, to exit editing mode
2.  Hold 'Shift' key and hit 'Z' key twice...

Vi exit without making any changes to the document
1.  Hit 'Esc' key twice, to exit editing mode
2.  Enter vi command mode by type in ':' and then type in 'q!' key and hit 'Enter' key to force quit vi without making any changes to the document.

DEVICE="em1p1"
ONBOOT="yes"
NM_CONTROLLED="yes"
TYPE=Ethernet
BOOTPROTO=none
:q!