don't believe the stupid people who say it's ok to not pay the loan. the insurance does not cover termination. when you applied for a loan, there normally is a clause in your salary letter (depending on where you're employed) saying that it is your employer's responsibility to inform the bank that you are leaving their services and/or your final dues will be paid to your bank account with them. you may need a clearance letter from the bank before you are able to leave qatar permanently.

you may be able to get away with a simple exit permit but you might become blacklisted and might never be given a visa to enter qatar or even the gcc again. also, they might have ways to find and go after you, you never know.