title: What is /dev/mapper/vg_root-lv_root directory? Why my docker relies on this directory?
body: <pre><code>    du
  </code></pre>
  
  <p>lists</p>
  
  <pre><code> Filesystem 1K-blocks Used   Available Use% Mounted on
  
   /dev/mapper/vg_root-lv_root 38929872   36450548     503672  99% /
  
   tmpfs 4025936               0    4025936   0% 
  
   /dev/shm /dev/sda1 53871    39618     201146  17% /boot
  
   xxx.in:/vol/software/arch*  653053184  408978688  244074496  63% /usr/software
  
   xxxx:/users003/gopir        3435973888 1024638080 2411335808  30% /u/gopir
  </code></pre>
  
  <p>I am not able to format it. In this case, my /dev/mapper/vg* is full. But i have space in my directory. How should i make use of my space? Why do my docker depends on this space rather than my space? Due to this, i get write error. I referred <a href="https://askubuntu.com/questions/296172/dev-mapper-full">this</a> but it doesn't help me. And what is this directory?</p>