    # File lib/fog/aws/requests/compute/create_volume.rb, line 49
            def create_volume(availability_zone, size, options = {})
              unless options.is_a?(Hash)
                Fog::Logger.deprecation("create_volume with a bare snapshot_id is deprecated, use create_volume(availability_zone, size, 'SnapshotId' => snapshot_id) instead [light_black](#{caller.first})[/]")
                options = { 'SnapshotId' => options }
              end

              response = Excon::Response.new
              if availability_zone && (size || options['SnapshotId'])
                snapshot = self.data[:snapshots][options['SnapshotId']]
                if options['SnapshotId'] && !snapshot
                  raise Fog::Compute::AWS::NotFound.new("The snapshot '#{options['SnapshotId']}' does not exist.")
                end

                if snapshot && size && size < snapshot['volumeSize']
                  raise Fog::Compute::AWS::NotFound.new("The snapshot '#{options['SnapshotId']}' has size #{snapshot['volumeSize']} which is greater than #{size}.")
                elsif snapshot && !size
                  size = snapshot['volumeSize']
                end

                if options['VolumeType'] == 'io1'
                  iops = options['Iops']
                  if !iops
                    raise Fog::Compute::AWS::Error.new("InvalidParameterCombination => The parameter iops must be specified for io1 volumes.")
                  end

                  if size < 10
                    raise Fog::Compute::AWS::Error.new("InvalidParameterValue => Volume of #{size}GiB is too small; minimum is 10GiB.")
                  end

                  if (iops_to_size_ratio = iops.to_f / size.to_f) > 10.0
                    raise Fog::Compute::AWS::Error.new("InvalidParameterValue => Iops to volume size ratio of #{"%.1f" % iops_to_size_ratio} is too high; maximum is 10.0")
                  end

                  if iops < 100
                    raise Fog::Compute::AWS::Error.new("VolumeIOPSLimit => Volume iops of #{iops} is too low; minimum is 100.")
                  end

                  if iops > 1000
                    raise Fog::Compute::AWS::Error.new("VolumeIOPSLimit => Volume iops of #{iops} is too high; maximum is 1000.")
                  end
                end

                response.status = 200
                volume_id = Fog::AWS::Mock.volume_id
                data = {
                  'availabilityZone'  => availability_zone,
                  'attachmentSet'     => [],
                  'createTime'        => Time.now,
                  'iops'              => options['Iops'],
                  'size'              => size,
                  'snapshotId'        => options['SnapshotId'],
                  'status'            => 'creating',
                  'volumeId'          => volume_id,
                  'volumeType'        => options['VolumeType'] || 'standard'
                }
                self.data[:volumes][volume_id] = data
                response.body = {
                  'requestId' => Fog::AWS::Mock.request_id
                }.merge!(data.reject {|key,value| !['availabilityZone','createTime','size','snapshotId','status','volumeId','volumeType'].include?(key) })
              else
                response.status = 400
                response.body = {
                  'Code' => 'MissingParameter'
                }
                unless availability_zone
                  response.body['Message'] = 'The request must contain the parameter availability_zone'
                else
                  response.body['Message'] = 'The request must contain the parameter size'
                end
              end
              response
            end