Openstack - Nova Evacuate without Shared Storage

What's this?

Nova instance が稼働している compute node が障害停止した際に、Nova instance を別の compute node 上に復旧(=退避)

• Shared storage 無しの場合、全く新しい Nova instance が別の compute node 上で起動される
• ただし、障害停止した compute node 上で稼働していた Nova instance の Parameter (id, hostname, uid, ip ...etc)が使用される
• データは引き継がれない

[条件]

• Shared storage なし
• Nova instance の全データは compute node の local disk にある
• 追加 Volume としての Cinder 未使用
• Hypervisor は KVM

Initial state

Compute node

# nova service-list | egrep "Host|nova-compute"
| Binary           | Host    | Zone     | Status  | State | Updated_at                 | Disabled Reason |
| nova-compute     | node-27 | nova     | enabled | up    | 2015-03-17T08:36:27.000000 | -               |
| nova-compute     | node-28 | nova     | enabled | up    | 2015-03-17T08:36:24.000000 | -               |
| nova-compute     | node-31 | nova2    | enabled | up    | 2015-03-17T08:36:24.000000 | -               |

AZ

# nova availability-zone-list | egrep -A 10 "^\| nova"
| nova                     | available                              |
| |- node-27               |                                        |
| | |- nova-compute        | enabled :-) 2015-03-17T08:36:37.000000 |
| |- node-28               |                                        |
| | |- nova-compute        | enabled :-) 2015-03-17T08:36:34.000000 |
| nova2                    | available                              |
| |- node-31               |                                        |
| | |- nova-compute        | enabled :-) 2015-03-17T08:36:34.000000 |
+--------------------------+----------------------------------------+

Nova instance is running on node-27

[root@node-17 ~]# nova list --field name,status,OS-EXT-STS:vm_state,OS-EXT-AZ:availability_zone,OS-EXT-SRV-ATTR:hypervisor_hostname
+--------------------------------------+------------+--------+----------------------+------------------------------+--------------------------------------+
| ID                                   | Name       | Status | OS-EXT-STS: Vm State | OS-EXT-AZ: Availability Zone | OS-EXT-SRV-ATTR: Hypervisor Hostname |
+--------------------------------------+------------+--------+----------------------+------------------------------+--------------------------------------+
| b103274a-fd6d-42cc-8cfb-c78f3d37c898 | admin_vm01 | ACTIVE | active               | nova                         | node-27                |
+--------------------------------------+------------+--------+----------------------+------------------------------+--------------------------------------+

Stop nova-compute service of node-27

Stop nova-compute service

# service openstack-nova-compute stop
Stopping openstack-nova-compute:                           [  OK  ]

# service openstack-nova-compute status
openstack-nova-compute is stopped

# nova service-list | egrep "Host|nova-compute"
| Binary           | Host    | Zone     | Status  | State | Updated_at                 | Disabled Reason |
| nova-compute     | node-27 | nova     | enabled | down  | 2015-03-17T08:38:17.000000 | -               |
| nova-compute     | node-28 | nova     | enabled | up    | 2015-03-17T08:37:14.000000 | -               |
| nova-compute     | node-31 | nova2    | enabled | up    | 2015-03-17T08:38:14.000000 | -               |

AZ

# nova availability-zone-list | egrep -A 10 "^\| nova"
| nova                     | available                              |
| |- node-27               |                                        |
| | |- nova-compute        | enabled XXX 2015-03-17T08:38:17.000000 |
| |- node-28               |                                        |
| | |- nova-compute        | enabled :-) 2015-03-17T08:37:14.000000 |
| nova2                    | available                              |
| |- node-31               |                                        |
| | |- nova-compute        | enabled :-) 2015-03-17T08:38:14.000000 |
+--------------------------+----------------------------------------+

Evacuate

Execute evacuate

Evacuate Nova instance to node-28

# nova evacuate b103274a-fd6d-42cc-8cfb-c78f3d37c898 node-28
+-----------+--------------+
| Property  | Value        |
+-----------+--------------+
| adminPass | EtDTWFzQAe8q |
+-----------+--------------+

Check the evacuate result

• Nova instance has same parameters (id, hostname, uid, ip ...etc) which previous Nova instance had.
• You can login to this instance by using above adminPass.

# nova list --field name,status,,OS-EXT-STS:vm_state,OS-EXT-AZ:availability_zone,OS-EXT-SRV-ATTR:hypervisor_hostname
+--------------------------------------+------------+--------+--+----------------------+------------------------------+--------------------------------------+
| ID                                   | Name       | Status |  | OS-EXT-STS: Vm State | OS-EXT-AZ: Availability Zone | OS-EXT-SRV-ATTR: Hypervisor Hostname |
+--------------------------------------+------------+--------+--+----------------------+------------------------------+--------------------------------------+
| b103274a-fd6d-42cc-8cfb-c78f3d37c898 | admin_vm01 | ACTIVE |  | active               | nova                         | node-28                              |
+--------------------------------------+------------+--------+--+----------------------+------------------------------+--------------------------------------+

Environment

• Openstack : Juno
• Ceph : Firefly

Reference

Openstack - Nova Evacuate with Shared Storage
Openstack - Nova Evacuate with Shared Storage with Cinder
Openstack - Nova Evacuate with Shared Storage with Cinder between AZ
Openstack - Nova Evacuate without Shared Storage
Openstack - Nova Host-Evacuate with Shared Storage
Openstack - Nova Host-Evacuate with Shared Storage between AZ