docs: function start(mode, target, system, containerDef, container, out, cb) {
  
      out.preview({cmd: 'start instances', host: null, user: null, keyPath: null});
      if (mode === 'preview') {
        return cb(null);
      }
  
      var instanceType = container.specific.InstanceType ||
                         container.specific.instanceType ||
                         config.defaultInstanceType ||
                         'm3.medium';
  
      var imageId = container.specific.ImageId ||
                    container.specific.imageId ||
                    config.defaultImageId;
  
      var params = {'MaxCount': 1,
                    'MinCount': 1,
                    'EbsOptimized': false,
                    'InstanceInitiatedShutdownBehavior': 'stop',
                    'InstanceType': instanceType,
                    'ImageId': imageId,
                    'KeyName': config.defaultKeyName,
                    'SubnetId': config.defaultSubnetId,
                    'Monitoring': { Enabled: false }};
                    /*'EbsOptimized': container.specific.ebsOptimized,
                    'InstanceInitiatedShutdownBehavior': container.specific.instanceInitiatedShutdownBehavior,
                    'InstanceType': container.specific.instanceType,
                    'KeyName': container.specific.keyName,
                    'Monitoring': container.specific.monitoring};*/
  
      if (system.topology.containers[container.containedBy].type === 'aws-sg') {
        params.SecurityGroupIds = [system.topology.containers[container.containedBy].nativeId];
      }
  
      _ec2.runInstances(params, function(err, data) {
        if (err) { return cb(err, null); }
        var instance = data.Instances[0];
  
        pollInstanceStart(instance, function(err, newSpecific) {
          if (err) { return cb(err); }
          var tagParams = {Resources: [instance.InstanceId], Tags: container.specific.tags || []};
          tagParams.Tags.push({Key: 'nscale-system', Value: system.name + '-' + system.topology.name});
          tagParams.Tags.push({Key: 'nscale-id', Value: system.name + '-' + system.topology.name + '-' + container.id});
          if (containerDef.name) {
            tagParams.Tags.push({Key: 'Name', Value: container.id});
          }
          _ec2.createTags(tagParams, function() {
            if (err) { return cb(err); }
            var c = _.find(system.topology.containers, function(cont) { return cont.id === container.id; });
            c.nativeId = instance.InstanceId;
            c.specific = newSpecific;
            system.dirty = true;
            cb(null, system);
          });
        });
      });
    }