Server Tomcat v7.0 Server at localhost was unable to start within 101 seconds. If the server requires more time, try increasing the timeout in the server edit
I was too facing similar issue and here I found another solution for it.
I have just started Eclipse Luna and not developed/deployed any project yet. I tried adding Tomcat v7.0 Server and got same error.
In order to resolve the issue I went to Server Perspective (it's actually server tab next to the console tab located below Project code). Double click on Server which is added to Eclipse. It will open up Overview page. Look for Server Location and select Use workspace metadata(does not modify Tomcat location). Now restart the Server and error will go away.
Server > (double click) Tomcat v7.0 Server at localhost > (Overview page) Server Location > Select -- Use workspace metadata(does not modify Tomcat location).