Here’s how to turn on Maintenance Mode in Drupal 7:

Step 1

• Go to “Configuration” then “Maintenance mode”.

Step 2

• Make sure the “Put site into maintenance mode” box is checked
• Enter the message you want visitors to see during the interruption.
• Click “Save configuration”.

Step 3

• You’ll now see a message saying “The configuration options have been saved”.

Step 4

• You will be able to browse around your site without problems but visitors who aren’t logged in will see the message above.
• If you log yourself and can’t get back in, just add /?q=user after your site address and you’ll be back to the user login page.