There are several ways to restart a Jenkins server:

Restart from the Jenkins UI:

• Log in to the Jenkins UI as an administrator.

• Click on "Manage Jenkins" in the left navigation menu.

• Click on "Restart" in the "System Information" section.

• Click on the "Yes" button in the confirmation dialog.

Restart from the command line:

• Connect to the Jenkins server via SSH.

• Run the systemctl restart jenkins command to restart the Jenkins service.

Restart from the Jenkins CLI:

• Run the java -jar jenkins-cli.jar -s http://jenkins-server:port/ restart command to restart the Jenkins server.

It is important to note that restarting the Jenkins server will interrupt any running builds and may cause other disruptions. You should only restart the Jenkins server if it is necessary for maintenance or troubleshooting purposes.