title: DF doesn't show swap partition
body: <p>I am using DF to check my disk usage and partition. Why doesn't it show my swap partition? I have 8GB for swap when I installed CentOS 7. </p>
  
  <pre><code>root@localhost abigail]# df -h
  Filesystem               Size  Used Avail Use% Mounted on
  /dev/mapper/centos-root  196G   30G  166G  16% /
  devtmpfs                 3.8G     0  3.8G   0% /dev
  tmpfs                    3.9G  130M  3.7G   4% /dev/shm
  tmpfs                    3.9G  8.9M  3.8G   1% /run
  tmpfs                    3.9G     0  3.9G   0% /sys/fs/cgroup
  /dev/sda1                2.0G  129M  1.9G   7% /boot
  /dev/mapper/centos-home  261G   54G  207G  21% /home
  </code></pre>