title: Where is the rootfs of container in host machine after docker 1.6.0
body: <p>In Docker <em>v1.4.1</em>, we can find the <em>rootfs</em> of a container on the host machine. For example:</p>
  
  <pre><code>cd /var/lib/docker/devicemapper/mnt/ab83a2638bb23f24d8811fa9b4ca458efca9269696ff3112cc670be2833f3f92/rootfs/
  .autofsck     .dockerenv    lost+found/   proc/         sys/
  .autorelabel  .dockerinit   media/        root/         tmp/
  bin/          etc/          mnt/          sbin/         usr/
  boot/         lib/          opt/          selinux/      var/
  dev/          lib64/        .pki/         srv/
  </code></pre>
  
  <p>But in Docker <em>v1.6.0</em>, I found that <code>/var/lib/docker/devicemapper/mnt/911d7ac8fca78b2beca8752ec89d80c06a1ea1dd8a65099d074ed40eec0c6cce</code> is empty.</p>
  
  <p>Where is it for <em>v1.6.0</em>?</p>
  
  <p>It's already used devicemapper</p>
  
  <pre><code># docker -D info
  Containers: 4
  Images: 58
  Storage Driver: devicemapper
    Pool Name: docker-253:1-2886824-pool
    Pool Blocksize: 65.54 kB
    Backing Filesystem: extfs
  Data file: /dev/loop0
  Metadata file: /dev/loop1
  Data Space Used: 12.12 GB
  Data Space Total: 107.4 GB
  Data Space Available: 95.26 GB
  Metadata Space Used: 10.48 MB
  Metadata Space Total: 2.147 GB
  Metadata Space Available: 2.137 GB
  Udev Sync Supported: true
  Data loop file: /var/lib/docker/devicemapper/devicemapper/data
  Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
  Library Version: 1.02.93 (2015-01-30)
  Execution Driver: native-0.2
  Kernel Version: 4.0.6-300.fc22.x86_64  
  Operating System: Fedora 22 (Twenty Two)
  CPUs: 2
  Total Memory: 3.705 GiB
  Name: rhel65.cn.ibm.com
  ID: WERO:NIMH:2K3M:GRGS:2Q5T:JDU4:QMO3:QFE5:QZJB:GICM:OLMS:7GFL
  Debug mode (server): false
  Debug mode (client): true
  Fds: 18
  Goroutines: 28
  System Time: Fri Aug  7 22:33:58 CST 2015
  EventsListeners: 0
  Init SHA1: a29656f0ad364f66e24c1ff1cf36b9e0e2bd5b0d
  Init Path: /usr/libexec/docker/dockerinit
  Docker Root Dir: /var/lib/docker
  </code></pre>