How to launch EC2 instance with Boto, specifying size of EBS?

You have to create a block device mapping first:

dev_sda1 = boto.ec2.blockdevicemapping.EBSBlockDeviceType()dev_sda1.size = 50 # size in Gigabytesbdm = boto.ec2.blockdevicemapping.BlockDeviceMapping()bdm['/dev/sda1'] = dev_sda1 

After this you can give the block device map in your run_instances call:

reservation = ec2.run_instances( image_id=AMI_ID,                                  key_name=EC2_KEY_HANDLE,                                  instance_type=INSTANCE_TYPE,                                 security_groups = [ SECGROUP_HANDLE, ],                                 block_device_mappings = [bdm])

Unfortunately this is not really well documented, but the example can be found in the source code.

You can also use CloudFormation, which is used to document and automate your environment.You can check the template for the ESB definition at: https://s3.amazonaws.com/cloudformation-templates-us-east-1/EC2WithEBSSample.template

 "Resources" : {    "Ec2Instance" : {      "Type" : "AWS::EC2::Instance",      "Properties" : {        "AvailabilityZone" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "TestAz" ]},        "SecurityGroups" : [ { "Ref" : "InstanceSecurityGroup" } ],        "KeyName" : { "Ref" : "KeyName" },        "ImageId" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "AMI" ]},        "Volumes" : [           { "VolumeId" : { "Ref" : "NewVolume" },            "Device" : "/dev/sdk"          }        ]      }    },    ...    "NewVolume" : {      "Type" : "AWS::EC2::Volume",      "Properties" : {        "Size" : "100",        "AvailabilityZone" : { "Fn::FindInMap" : [ "RegionMap", { "Ref" : "AWS::Region" }, "TestAz" ]}      }    }

You can then use Boto CloudFormation API to deploy your environment.