code: def update(kernel=False):
      
      manager = MANAGER
      cmds = {'yum -y --color=never': {False: '--exclude=kernel* update', True: 'update'}}
      cmd = cmds[manager][kernel]
      run_as_root("%(manager)s %(cmd)s" % locals())
docs: Upgrade all packages, skip obsoletes if ``obsoletes=0`` in ``yum.conf``.
  
      Exclude *kernel* upgrades by default.