Openstack 中, 创建云主机时, 需要定义 flavor 类型, flavor 定义了每个云主机的硬件类型, 包括 cpu 个数, 内存大小, 硬盘大小(根盘), 作为通用类型, 我们不会把硬盘容量设定过大, 那么对于数据库用户或其他需要使用大容量磁盘的用户是不合适的.

特点:

云主机与云硬盘, 需要独立地创建, 独立管理

云硬盘需要通过命令指定云主机进行连接方可使用

云主机被删除, 云硬盘数据依旧存在

每个云硬盘只可以与一个云主机进行连接, 不可并发同时访问

云硬盘数据永久保存(除非手动删除)

云主机硬盘创建在计算节点上, 云硬盘创建在共享存储中(ceph)

Openstack 中, 利用 cinder 命令对云硬盘进行增删改操作, 使用 nova命令对云主机中对云硬盘进行管理

Cinder 类型

[root@hh-yun-puppet-129021 ~(keystone_admin)]# cinder type-list
+--------------------------------------+----------------+
|                  ID                  |      Name      |
+--------------------------------------+----------------+
| 45fdd68a-ca0f-453c-bd10-17e826a1105e |   CEPH-SATA    |
| 4a323411-cd36-4282-b29d-c2f2d24191e9 | GLUSTERFS-SSD  |
| 919dc90f-c559-44c9-bc68-2d1dfbe3cf8a | GLUSTERFS-SATA |
+--------------------------------------+----------------+

当前生产环境下, 只使用到 CEPH-SATA 类型, GLUSTERFS 类型都已启用

在利用 cinder 命令创建云硬盘时, 我们需要指定 cinder type 的命名, 就是 CEPH-SATA

Cinder 后端服务

[root@hh-yun-puppet-129021 ~(keystone_admin)]# cinder service-list
+------------------+-------------------------------------+------+---------+-------+----------------------------+-----------------+
|      Binary      |                 Host                | Zone |  Status | State |         Updated_at         | Disabled Reason |
+------------------+-------------------------------------+------+---------+-------+----------------------------+-----------------+
|  cinder-backup   |      hh-yun-cinder.vclound.com      | nova | enabled |   up  | 2016-03-15T07:04:21.000000 |       None      |
| cinder-scheduler |      hh-yun-cinder.vclound.com      | nova | enabled |   up  | 2016-03-15T07:04:15.000000 |       None      |
|  cinder-volume   | hh-yun-cinder.vclound.com@CEPH_SATA | nova | enabled |   up  | 2016-03-15T07:04:19.000000 |       None      |
+------------------+-------------------------------------+------+---------+-------+----------------------------+-----------------+

请留意
cinder-volume 进程的host 定义, cinder-volume 服务在收到指定, 对云硬盘进行增删改操作时候, 需要找到 host (hh-yun-cinder.vclound.com@CEPH_SATA ), 配置文件(/etc/cinder/cinder.conf)中已完成定义.

创建云硬盘

cinder create --display-name 'user for db' --volume-type CEPH-SATA 20
+--------------------------------+--------------------------------------+
|            Property            |                Value                 |
+--------------------------------+--------------------------------------+
|          attachments           |                  []                  |
|       availability_zone        |                 nova                 |
|            bootable            |                false                 |
|           created_at           |      2016-03-14T09:24:52.000000      |
|      display_description       |                 None                 |
|          display_name          |             user for db              |
|           encrypted            |                False                 |
|               id               | d1e1194f-d33b-4169-9ce2-6644fa111d89 |
|            metadata            |       {u'readonly': u'False'}        |
|     os-vol-host-attr:host      | hh-yun-cinder.vclound.com@CEPH_SATA  |
| os-vol-mig-status-attr:migstat |                 None                 |
| os-vol-mig-status-attr:name_id |                 None                 |
|  os-vol-tenant-attr:tenant_id  |   bb0b51d166254dc99bc7462c0ac002ff   |
|              size              |                  20                  |
|          snapshot_id           |                 None                 |
|          source_volid          |                 None                 |
|             status             |              available               |
|            user_id             |   226e71f1c1aa4bae85485d1d17b6f0ae   |
|          volume_type           |              CEPH-SATA               |
+--------------------------------+--------------------------------------+

历史: 云平台早期同时使用了clusterfs 后端 ceph 后端两种, 后来过度只使用 ceph 后端

[root@hh-yun-puppet-129021 ~(keystone_admin)]# cinder list --display-name 'user for db'
+--------------------------------------+-----------+--------------+------+-------------+----------+-------------+
|                  ID                  |   Status  | Display Name | Size | Volume Type | Bootable | Attached to |
+--------------------------------------+-----------+--------------+------+-------------+----------+-------------+
| d1e1194f-d33b-4169-9ce2-6644fa111d89 | available | user for db  |  20  |  CEPH-SATA  |  false   |             |
+--------------------------------------+-----------+--------------+------+-------------+----------+-------------+

挂载云盘
参考主机状态

[root@hh-yun-puppet-129021 ~(keystone_admin)]# nova show 7dcfee9a-9338-489b-a335-215b8441d67b | grep -E 'volumes_attached|vm_state|name'
| OS-EXT-SRV-ATTR:hypervisor_hostname  | hh-yun-compute-130214.vclound.com                            |
| OS-EXT-SRV-ATTR:instance_name        | instance-00017faf                                            |
| OS-EXT-STS:vm_state                  | active                                                       |
| key_name                             | -                                                            |
| name                                 | terry.gz.vclound.com                                         |
| os-extended-volumes:volumes_attached | []                                                           |

利用 nova volume-attach 云主机id 云盘id 进行挂载

nova volume-attach 7dcfee9a-9338-489b-a335-215b8441d67b d1e1194f-d33b-4169-9ce2-6644fa111d89
+----------+--------------------------------------+
| Property | Value                                |
+----------+--------------------------------------+
| device   | /dev/vdc                             |
| id       | d1e1194f-d33b-4169-9ce2-6644fa111d89 |
| serverId | 7dcfee9a-9338-489b-a335-215b8441d67b |
| volumeId | d1e1194f-d33b-4169-9ce2-6644fa111d89 |
+----------+--------------------------------------+

挂载后, 再次参考主机状态

[root@hh-yun-puppet-129021 ~(keystone_admin)]# nova show 7dcfee9a-9338-489b-a335-215b8441d67b | grep -E 'volumes_attached|vm_state|name'
| OS-EXT-SRV-ATTR:hypervisor_hostname  | hh-yun-compute-130214.vclound.com                            |
| OS-EXT-SRV-ATTR:instance_name        | instance-00017faf                                            |
| OS-EXT-STS:vm_state                  | active                                                       |
| key_name                             | -                                                            |
| name                                 | terry.gz.vclound.com                                         |
| os-extended-volumes:volumes_attached | [{"id": "d1e1194f-d33b-4169-9ce2-6644fa111d89"}]             |

参考 volumes_attached 状态栏中, 出现了挂载了的云盘
假如有多个云硬盘被挂载, 该状态栏将会出现多个云盘 ID

卸载云盘

nova volume-detach 7dcfee9a-9338-489b-a335-215b8441d67b d1e1194f-d33b-4169-9ce2-6644fa111d89

数据库分析
参考下面信息

已经把云盘挂载到云主机中 /dev/vdc 设备中

云盘信息在数据库中主要体现在两个表中
1. cinder.volumes (云盘创建后, 会在该表中添加云盘记录数据)
2. nova. block_device_mapping (云盘挂载后, 会在该表中添加挂载记录)

如上文, 创建了 user for db 云盘, 参考下面记录

mysql> select created_at, deleted, id, user_id, project_id, host, size, mountpoint, status, attach_time, display_name, attached_host from cinder.volumes where id='d1e1194f-d33b-4169-9ce2-6644fa111d89' \G
*************************** 1. row ***************************
   created_at: 2016-03-14 09:24:52
      deleted: 0
           id: d1e1194f-d33b-4169-9ce2-6644fa111d89
      user_id: 226e71f1c1aa4bae85485d1d17b6f0ae
   project_id: bb0b51d166254dc99bc7462c0ac002ff
         host: hh-yun-cinder.vclound.com@CEPH_SATA
         size: 20
   mountpoint: NULL
       status: available
  attach_time: NULL
 display_name: user for db
attached_host: NULL
1 row in set (0.00 sec)

注意, 当云盘被删除后, 上述数据中, deleted 显示非0 状态, status 显示 deleted 状态

当云盘挂载成功后, 参考下面表数据信息

mysql> select created_at, device_name, volume_id, volume_size, instance_uuid, deleted  from nova.block_device_mapping where volume_id='d1e1194f-d33b-4169-9ce2-6644fa111d89' and deleted =0  \G
*************************** 1. row ***************************
   created_at: 2016-03-15 07:24:38
  device_name: /dev/vdc
    volume_id: d1e1194f-d33b-4169-9ce2-6644fa111d89
  volume_size: NULL
instance_uuid: 7dcfee9a-9338-489b-a335-215b8441d67b
      deleted: 0
1 row in set (0.00 sec)

注意, 当云盘被卸载后, deleted 显示非0 状态