若不指定，建立系统卷下载镜像，虚拟机删除时删除系统卷；
若指定，命令以下：
nova boot --image <image_id> --flavor 2 --key-name mykey --block-device-mapping vda=<vol_id>:<type>:<size>:<delete-on-terminate> <instance_name>
此时忽略image参数，type是snap或空；size尽可能是空；（2013.06.08）G版能够不填--image <id>

一个例子：

nova boot kong2 --flavor 6 --nic port-id=93604ec4-010e-4fa5-a792-33901223313b --key-name mykey --block-device-mapping vda=b66e294e-b997-48c1-9208-817be475e95b:::0

root@controller231:~# nova show kong2
+-------------------------------------+----------------------------------------------------------+
| Property                            | Value                                                    |
+-------------------------------------+----------------------------------------------------------+
| status                              | ACTIVE                                                   |
| updated                             | 2013-06-26T10:01:29Z                                     |
| OS-EXT-STS:task_state               | None                                                     |
| OS-EXT-SRV-ATTR:host                | controller231                                            |
| key_name                            | mykey                                                    |
| image                               | Attempt to boot from volume - no image supplied          |
| hostId                              | 083729f2f8f664fffd4cffb8c3e76615d7abc1e11efc993528dd88b9 |
| OS-EXT-STS:vm_state                 | active                                                   |
| OS-EXT-SRV-ATTR:instance_name       | instance-00000021                                        |
| OS-EXT-SRV-ATTR:hypervisor_hostname | controller231.openstack.org                              |
| flavor                              | kong_flavor (6)                                          |
| id                                  | 8989a10b-5a89-4f87-9b59-83578eabb997                     |
| security_groups                     | [{u'name': u'default'}]                                  |
| user_id                             | f882feb345064e7d9392440a0f397c25                         |
| name                                | kong2                                                    |
| created                             | 2013-06-26T10:00:51Z                                     |
| tenant_id                           | 6fbe9263116a4b68818cf1edce16bc4f                         |
| OS-DCF:diskConfig                   | MANUAL                                                   |
| metadata                            | {}                                                       |
| accessIPv4                          |                                                          |
| accessIPv6                          |                                                          |
| testnet01 network                   | 10.1.1.6                                                 |
| progress                            | 0                                                        |
| OS-EXT-STS:power_state              | 1                                                        |
| OS-EXT-AZ:availability_zone         | nova                                                     |
| config_drive                        |                                                          |
+-------------------------------------+----------------------------------------------------------+

此时，传递给nova driver的block_device_info结构体：

{
	'block_device_mapping': [{
		'connection_info': {
			u'driver_volume_type': u'iscsi',
			'serial': u'b66e294e-b997-48c1-9208-817be475e95b',
			u'data': {
				u'target_discovered': False,
				u'target_iqn': u'iqn.2010-10.org.openstack: volume-b66e294e-b997-48c1-9208-817be475e95b',
				u'target_portal': u'192.168.82.231: 3260',
				u'volume_id': u'b66e294e-b997-48c1-9208-817be475e95b',
				u'target_lun': 1,
				u'auth_password': u'jcYpzNiA4ZQ4dyiC26fB',
				u'auth_username': u'CQZto4sC4HKkx57U4WfX',
				u'auth_method': u'CHAP'
			}
		},
		'mount_device': u'vda',
		'delete_on_termination': False
	}],
	'root_device_name': None,
	'ephemerals': [],
	'swap': None
}

在nova-compute中由ComputeManager对象的_setup_block_device_mapping方法处理，会调用Cinder的initialize_connection()和attach()。调用过程：
cinder-api --(RPC)--> 卷所在主机上的cinder-volume--> driver
initialize_connection方法返回：

connection_info：
{
    'driver_volume_type':'iscsi',
    'data': {
       'target_discovered': False,
       'target_iqn': 'iqn.2010-10.org.openstack:volume-a242e1b2-3f3f-42af-84a3-f41c87e19c2b',
       'target_portal': '182.168.61.24:3260',
       'volume_id': a242e1b2-3f3f-42af-84a3-f41c87e19c2b
    }
}

attach方法：修改数据表volumes的status(in-use)、mountpoint(vda)、attach_status(attached)、instance_uuid字段

5.3.2 aggregate

相关接口都是管理员接口，最初是用来使用Xen hypervisor resource pools。相关的配置：
在scheduler_default_filters配置项加入AggregateInstanceExtraSpecsFilter

工做流：

$ nova aggregate-create fast-io nova
+----+---------+-------------------+-------+----------+
| Id | Name    | Availability Zone | Hosts | Metadata |
+----+---------+-------------------+-------+----------+
| 1  | fast-io | nova              |       |          |
+----+---------+-------------------+-------+----------+
$ nova aggregate-set-metadata 1 ssd=true(若是value为None，则删除该key)
+----+---------+-------------------+-------+-------------------+
| Id | Name    | Availability Zone | Hosts | Metadata          |
+----+---------+-------------------+-------+-------------------+
| 1  | fast-io | nova              | []    | {u'ssd': u'true'} |
+----+---------+-------------------+-------+-------------------+
$ nova aggregate-add-host 1 node1(主机必须与aggregate在同一个zone)
+----+---------+-------------------+-----------+-------------------+
| Id | Name    | Availability Zone | Hosts      | Metadata          |
+----+---------+-------------------+------------+-------------------+
| 1  | fast-io | nova              | [u'node1'] | {u'ssd': u'true'} |
+----+---------+-------------------+------------+-------------------+
# nova-manage instance_type set_key --name=<flavor_name>  --key=ssd --value=true，或者使用：
# nova flavor-key 1 set ssd=true

root@controller60:~/controller# nova aggregate-create my_aggregate my_zone
+----+--------------+-------------------+-------+----------+
| Id | Name         | Availability Zone | Hosts | Metadata |
+----+--------------+-------------------+-------+----------+
| 2  | my_aggregate | my_zone           |       |          |
+----+--------------+-------------------+-------+----------+

root@controller60:~/controller# nova aggregate-details 2
+----+--------------+-------------------+-------+------------------------------------+
| Id | Name         | Availability Zone | Hosts | Metadata                           |
+----+--------------+-------------------+-------+------------------------------------+
| 2  | my_aggregate | my_zone           | []    | {u'availability_zone': u'my_zone'} |
+----+--------------+-------------------+-------+------------------------------------+

此时，zone只是aggregate的metadata中的选项之一。

5.3.3 指定主机建立

管理员操做
nova boot --image aee1d242-730f-431f-88c1-87630c0f07ba --flavor 1 --availability-zone nova:<host_name> testhost 

5.3.4 注入

虚拟机建立时能够向虚拟机镜像中注入key、password、net、metadata、files内容；

user data：虚拟机能够经过查询metadata service或从config-drive获取user data，好比在虚拟机内部执行：
$ curl http://169.254.169.254/2009-04-04/user-data
This is some text
$ curl http://169.254.169.254/openstack/2012-08-10/user_data
This is some text

user data和cloud-init则容许配置虚拟机启动时的行为，Cloud-init是Canonical的一个开源工程，Utuntu镜像中都预装了cloud-init，与Compute metadata service和Compute config drive兼容。cloud-init可以识别以#!（执行脚本，至关于写一个/etc/rc.local脚本）或#cloud-config（能够与Puppet或Chef配合）开头的内容。

Config drive：能够传递一些内容，虚拟机启动时挂载并读取信息。好比当DHCP不可用时，能够向config drive传入网络配置。cloud-init能够自动从config drive获取信息，若是镜像没有安装cloud-init，则须要自定义脚本挂载config drive，读取数据，执行任务。
一个复杂的建立虚拟机示例：
nova boot --config-drive=true --image my-image-name --key-name mykey --flavor 1 --user-data ./my-user-data.txt myinstance --file /etc/network/interfaces=/home/myuser/instance-interfaces --file known_hosts=/home/myuser/.ssh/known_hosts --meta role=webservers --meta essential=false
全部指定的信息均可以从config drive获取。
也能够指定配置项：force_config_drive=true，老是建立config drive
在虚拟机内部访问config drive：
# mkdir -p /mnt/config
# mount /dev/disk/by-label/config-2 /mnt/config
若是操做系统没有使用udev，目录/dev/disk/by-label可能不存在，能够用：
# blkid -t LABEL="config-2" -odevice
查看config drive对应的卷标，而后执行：
# mkdir -p /mnt/config
# mount /dev/vdb /mnt/config
config drive中的内容（执行上述建立虚拟机命令后）：
ec2/2009-04-04/meta-data.json
ec2/2009-04-04/user-data
ec2/latest/meta-data.json
ec2/latest/user-data
openstack/2012-08-10/meta_data.json
openstack/2012-08-10/user_data
openstack/content
openstack/content/0000
openstack/content/0001
openstack/latest/meta_data.json
openstack/latest/user_data
ec2开头的记录会在未来移除，选择版本号最高的记录，如openstack/2012-08-10/meta_data.json文件内容（与openstack/latest/meta_data.json内容相同）：

openstack/2012-08-10/user_data文件（内容同openstack/latest/user_data）在有--user-data时才会建立，包含参数中传递的文件内容。

(2013.06.27)对于注入的key、userdata等内容的获取，G版中提供了新的实现方式，能够参见metadata在OpenStack中的使用（一）。（2013.07.23）对于Ubuntu镜像，注入SSH有一些限制：

Ubuntu cloud images do not have any ssh HostKey generated inside them
(/etc/ssh/ssh_host_{ecdsa,dsa,rsa}_key). The keys are generated by
cloud-init after it finds a metadata service. Without a metadata service,
they do not get generated. ssh will drop your connections immediately
without HostKeys.
https://lists.launchpad.net/openstack/msg12202.html

5.3.5 request_network（G版）

{
	id: XXX,
	address: XXX(mac),
	type: XXX(ovs or bridge or others),
	ovs_interfaceid: XXX(portid or none),
	devname: XXX('tap+portid'),
	network: {
		id: XXX,
		bridge: XXX('br-int' or 'brq+netid'),
		injected: XXX,
		label: XXX,
		tenant_id: XXX,
		should_create_bridge: XXX(true or none),
		subnets: [subnet: {
			cidr: XXX,
			gateway: {
				address: XXX,
				type: 'gateway'
			},
			dhcp_server: XXX,
			dns: [dns: {
				address: XXX,
				type='dns'
			}],
			ips: [ip: {
				address: XXX,
				type: 'fixed',
				floating_ips: {
					address: XXX,
					type='floating'
				}
			}],
			routes: []
		}]
	}
}

5.3.6 Cinder