title: docker service started, but daemon still has not been started in RHEL 7 VM
body: <p>For some reason, I hosted docker in a VM (RHEL 7). </p>
  
  <p>After installed docker 1.8, the service can be started correctly, but when I call docker info or some related command, it tells me that daemon has been started. </p>
  
  <p>But when I start docker daemon manually by command "docker daemon", it can be started smoothly and just with a warning, and it works well to run or search a image.</p>
  
  <p>So currently my issues is once I start the docker daemon in one putty session, I can execute docker related operation through another session, but once I closed the session with daemon started, all ended.</p>
  
  <p>Searched a lot, but seems have not found a good solution yet. Thanks ahead.   </p>
  
  <p>Attached some environment information:</p>
  
  <p>docker daemon:</p>
  
  <pre><code>[root@localhost ~]# docker daemon&lt;&gt;
  INFO[0000] Listening for HTTP on unix (/var/run/docker.sock)
  INFO[0000] [graphdriver] using prior storage driver "devicemapper"
  INFO[0000] Option DefaultDriver: bridge
  INFO[0000] Option DefaultNetwork: bridge
  WARN[0000] Running modprobe bridge nf_nat br_netfilter failed with message: modprobe: WARNING: Module br_netfilt
  , error: exit status 1
  INFO[0000] Firewalld running: false
  INFO[0000] Loading containers: start.
  ............................ERRO[0000] Error unmounting device 292a999f0e633020b435c6199958d4fccb1f4a3ca0a3ccc428d4fccb1f4a3ca0a3ccc42e38cba208a137c2
  INFO[0000] Loading containers: done.
  INFO[0000] Daemon has completed initialization
  INFO[0000] Docker daemon                                 commit=d12ea79 execdriver=native-0.2 graphdriver=device
  INFO[0032] GET /v1.20/images/json
  INFO[0040] GET /v1.20/containers/json?all=1
  292a999f0e633020b435c6199958d4fccb1f4a3ca0a3ccc42e38cba208a137c2INFO[0096] GET /v1.20/containers/292a999f0e63302
  INFO[0151] GET /v1.20/containers/292a999f0e63/json
  </code></pre>
  
  <p>docker info:<br></p>
  
  <pre><code>*[root@localhost ~]# docker info
  Containers: 14
  Images: 15
  Storage Driver: devicemapper
   Pool Name: docker-253:4-1073748960-pool
   Pool Blocksize: 65.54 kB
   Backing Filesystem: xfs
   Data file: /dev/loop1
   Metadata file: /dev/loop2
   Data Space Used: 3.016 GB
   Data Space Total: 107.4 GB
   Data Space Available: 104.4 GB
   Metadata Space Used: 3.351 MB
   Metadata Space Total: 2.147 GB
   Metadata Space Available: 2.144 GB
   Udev Sync Supported: true
   Deferred Removal Enabled: false
   Data loop file: /var/lib/docker/devicemapper/devicemapper/data
   Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
   Library Version: 1.02.93-RHEL7 (2015-01-28)
  Execution Driver: native-0.2
  Logging Driver: json-file
  Kernel Version: 3.10.0-123.el7.x86_64
  Operating System: Red Hat Enterprise Linux Server 7.0 (Maipo)
  CPUs: 10
  Total Memory: 9.609 GiB
  Name: localhost.localdomain
  ID: U5OY:WDSL:5IP3:2UFW:XYP6:3B2J:WJS4:6QY6:QDKL:MIFN:G452:QI33
  WARNING: bridge-nf-call-iptables is disabled
  WARNING: bridge-nf-call-ip6tables is disabled*
  </code></pre>