title: Why did my docker volume run out of disk space?
body: <p>I am using a persistent volume. While mounted in a container, I got an error message that there was no space left on the device. On inspection, the volume size was 256GB. However, there is much more room on the host. </p>
  
  <p>Some further details: The docker storage driver is <code>overlay2</code>. <code>df</code> reveals that there is a filesystem <code>/dev/mapper/vg1-docker</code> that is 256GB. During a download (over the internet) this filesystem became 100% full and <code>docker</code> did not automatically resize the filesystem to make more space, even though there was much more space available on the host. </p>
  
  <p>The host is native linux (ubuntu). Here is the output of <code>df -i</code>:</p>
  
  <pre><code>Filesystem               Inodes  IUsed    IFree IUse% Mounted on
  udev                   24754746    429 24754317    1% /dev
  tmpfs                  24757974    762 24757212    1% /run
  /dev/xvda2              6537216 142008  6395208    3% /
  tmpfs                  24757974      1 24757973    1% /dev/shm
  tmpfs                  24757974      3 24757971    1% /run/lock
  tmpfs                  24757974     18 24757956    1% /sys/fs/cgroup
  /dev/mapper/vg1-docker 16384000 985506 15398494    7% /var/lib/docker
  /dev/xvda1                65536    313    65223    1% /boot
  tmpfs                  24757974     10 24757964    1% /run/user/1001
  </code></pre>
  
  <p>I can't find any information on increasing the size of a docker volume.</p>
  
  <p>Note this is <em>not</em> a duplicate of <a href="https://stackoverflow.com/questions/42703481/why-has-docker-volume-run-out-of-space">Why has Docker volume run out of space?</a>.</p>