Modo mantenimiento via drush

https://www.drupal.org/docs/user_guide/en/extend-maintenance.html#s-enabling-or-disabling-maintenance-mode-using-drush

 

Enabling or disabling maintenance mode using Drush

  1. Follow the user interface steps above to edit the site maintenance message, if desired.

  2. Run the following Drush commands to enable maintenance mode and clear the cache:

    drush config:set system.maintenance message "Optional message" -y
drush state:set system.maintenance_mode 1 --input-format=integer
drush cache:rebuild

  3. Run the following Drush commands to disable maintenance mode and clear the cache:

    drush state:set system.maintenance_mode 0 --input-format=integer
drush cache:rebuild
  4. After running either set of commands, verify that your site is either in or out of maintenance mode by visiting the site in a browser where you are not logged in.