title: Can't start MongoDB on CentOS7
body: <p>I have a CentOS 7 empty VM.</p>
  
  <pre><code>&gt; hostnamectl
  ...
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.18.26-guest-4-4751b4a-x86_64
      Architecture: x86_64
  </code></pre>
  
  <p>I've installed MongoDB.</p>
  
  <pre><code>&gt; mongod --version
  db version v3.0.11
  git version: 48f8b49dc30cc2485c6c1f3db31b723258fcbf39
  </code></pre>
  
  <p>The config file:</p>
  
  <pre><code>&gt; cat /etc/mongod.conf
  # mongod.conf
  
  # for documentation of all options, see:
  #   http://docs.mongodb.org/manual/reference/configuration-options/
  
  # where to write logging data.
  systemLog:
    destination: file
    logAppend: true
    path: /mongo/logs #/var/log/mongodb/mongod.log
  
  # Where and how to store data.
  storage:
    dbPath: /mongo/data # (default) /var/lib/mongo
    journal:
      enabled: true
  #  engine:
  #  mmapv1:
  #  wiredTiger:
  
  # how the process runs
  processManagement:
    fork: true  # fork and run in background
    pidFilePath: /var/run/mongodb/mongod.pid  # location of pidfile
  
  # network interfaces
  net:
    port: 27017
    bindIp: 127.0.0.1  # Listen to local interface only, comment to listen on all interfaces.
  
  #security:
  #operationProfiling:
  #replication:
  #sharding:
  ## Enterprise-Only Options
  #auditLog:
  #snmp:
  </code></pre>
  
  <p>When I try to start I get this error:</p>
  
  <pre><code>&gt; service mongod start
     Starting mongod (via systemctl):  Job for mongod.service failed. See 'systemctl status mongod.service' and 'journalctl -xn' for details
  </code></pre>
  
  <p>and:</p>
  
  <pre><code>&gt; journalctl -xn
  -- Subject: Unit mongod.service has begun with start-up
  -- Defined-By: systemd
  -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
  -- 
  -- Unit mongod.service has begun starting up.
  avril 02 14:03:06 keystone runuser[30886]: pam_unix(runuser:session): session opened for user mongod by (uid=0)
  avril 02 14:03:06 keystone runuser[30886]: pam_unix(runuser:session): session closed for user mongod
  avril 02 14:03:06 keystone mongod[30879]: Starting mongod: [FAILED]
  avril 02 14:03:06 keystone systemd[1]: mongod.service: control process exited, code=exited status=1
  avril 02 14:03:06 keystone systemd[1]: Failed to start SYSV: Mongo is a scalable, document-oriented database..
  -- Subject: Unit mongod.service has failed
  -- Defined-By: systemd
  -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
  -- 
  -- Unit mongod.service has failed.
  -- 
  -- The result is failed.
  avril 02 14:03:06 keystone systemd[1]: Unit mongod.service entered failed state.
  </code></pre>
  
  <p>Has anyone encountered the issue "Failed to start SYSV"? </p>
  
  <p>Any help or hint is welcome.
  Thanks, Paul</p>