title: Docker driver "overlay2" failed to remove root filesystem: unlinkat - device or resource busy
body: <p>When trying to remove a docker container (for example when trying to <code>docker-compose down</code>) I always get these errors:</p>
  <pre><code>ERROR: for &lt;my_container&gt;  container d8424f80ef124c2f3dd8f22a8fe8273f294e8e63954e7f318db93993458bac27: driver &quot;overlay2&quot; failed to remove root filesystem: unlinkat /var/lib/docker/overlay2/64311f2ee553a5d42291afa316db7aa392a29687ffa61971b4454a9be026b3c4/merged: device or resource busy
  </code></pre>
  <p>Common advice like restarting the docker service, pruning or force removing the containers doesn't work. The only thing that I found that works is manually unmounting with <code>sudo umount /home/virtfs/xxxxx/var/lib/docker/overlay2/&lt;container_id&gt;/merged</code>, then I'm able to remove the container.</p>
  <p>My OS is <code>CentOS Linux release 7.9.2009 (Core)</code> with kernel version <code>3.10.0-1127.19.1.el7.x86_64</code>. I thought this was maybe due to overlay2 clashing with CentOS, but according to <a href="https://docs.docker.com/storage/storagedriver/overlayfs-driver/" rel="nofollow noreferrer">this page</a> my CentOS/kernel version should work. It would be great to find a solution to this, because I ideally want to <code>docker-compose down</code> without having to use elevated privileges to umount beforehand.</p>