When administering Portal for ArcGIS, occasionally you'll need to start and stop your portal to perform maintenance or configure advanced settings.
Portal for ArcGIS runs as the account that was used to install the software. This is known as the Portal for ArcGIS account. You'll need to log in to the machine hosting portal as the installation owner account and use the command line scripts stopportal.sh and startportal.sh to stop or start your portal. These scripts are located in the root folder of the Portal for ArcGIS installation directory.