In previous versions of SCCM extending the size of the log files was as easy as open SCCM Service Manager, selecting the component, and increase the log file.
That doesn’t work in SCCM CB. My friend Garth Jones @GarthMJ has a great post on how to get more out of your log files.
http://www.enhansoft.com/blog/how-to-increase-the-size-of-sccm-2012-site-server-log-files