What's this?

Take a snapshot of Nova instance
Restore from the snapshot (= Create new Nova instance)

Take a snapshot of Nova instance

Initial state

# nova list
+--------------------------------------+------------+--------+------------+-------------+---------------------+
| ID                                   | Name       | Status | Task State | Power State | Networks            |
+--------------------------------------+------------+--------+------------+-------------+---------------------+
| 7961383e-7528-4e26-8889-ab452bae0e7f | admin_vm01 | ACTIVE | -          | Running     | net04=192.168.12.78 |
+--------------------------------------+------------+--------+------------+-------------+---------------------+

Take a snapshot

# nova image-create --poll admin_vm01 admin_vm01_ss
Server snapshotting... 100% complete
Finished


# nova help image-create
usage: nova image-create [--show] [--poll] <server> <name>

Create a new image by taking a snapshot of a running server.

Positional arguments:
  <server>  Name or ID of server.
  <name>    Name of snapshot.

Optional arguments:
  --show    Print image info.
  --poll    Blocks while server snapshots so progress can be reported.

Check the snapshot

Nova command

# nova image-list | egrep "ID|admin_vm01_ss"
| ID                                   | Name                                     | Status | Server                               |
| 88648405-a9f5-40ae-bfb0-0ff2d7608258 | admin_vm01_ss                            | ACTIVE | 7961383e-7528-4e26-8889-ab452bae0e7f |

Glance command

# glance image-list | egrep "ID|admin_vm01_ss"
| ID                                   | Name                                     | Disk Format | Container Format | Size       | Status |
| 88648405-a9f5-40ae-bfb0-0ff2d7608258 | admin_vm01_ss                            | raw         | bare             | 1073741824 | active |

# glance image-show admin_vm01_ss
+---------------------------------------+--------------------------------------+
| Property                              | Value                                |
+---------------------------------------+--------------------------------------+
| Property 'base_image_ref'             | a5232547-4ccf-4ebb-9ab8-79e4daf73e9d |
| Property 'description'                | cirros-changed-password              |
| Property 'image_location'             | snapshot                             |
| Property 'image_state'                | available                            |
| Property 'image_type'                 | snapshot                             |
| Property 'instance_type_ephemeral_gb' | 0                                    |
| Property 'instance_type_flavorid'     | 318a3051-4304-4f3a-bda7-6f3a7637152b |
| Property 'instance_type_id'           | 2                                    |
| Property 'instance_type_memory_mb'    | 256                                  |
| Property 'instance_type_name'         | m1.nano                              |
| Property 'instance_type_root_gb'      | 1                                    |
| Property 'instance_type_rxtx_factor'  | 1.0                                  |
| Property 'instance_type_swap'         | 0                                    |
| Property 'instance_type_vcpus'        | 1                                    |
| Property 'instance_uuid'              | 7961383e-7528-4e26-8889-ab452bae0e7f |
| Property 'network_allocated'          | True                                 |
| Property 'owner_id'                   | a8085d1871f847bdb906ef4a28d1bd48     |
| Property 'user_id'                    | a1c2ec19759040e39f219fcf82028bf6     |
| checksum                              | 1fdf144151c4cb2350dbd6955576dcf9     |
| container_format                      | bare                                 |
| created_at                            | 2015-02-17T02:45:33                  |
| deleted                               | False                                |
| disk_format                           | raw                                  |
| id                                    | 88648405-a9f5-40ae-bfb0-0ff2d7608258 |
| is_public                             | False                                |
| min_disk                              | 1                                    |
| min_ram                               | 0                                    |
| name                                  | admin_vm01_ss                        |
| owner                                 | a8085d1871f847bdb906ef4a28d1bd48     |
| protected                             | False                                |
| size                                  | 1073741824                           |
| status                                | active                               |
| updated_at                            | 2015-02-17T02:46:26                  |
+---------------------------------------+--------------------------------------+

Restore from the snapshot (= Create new Nova instance)

Check necessary information

Network

# neutron net-list | egrep " id |net04"
| id                                   | name           | subnets                                               |
| b3fa9d4d-4c21-47f5-be07-cf2ff518035e | net04          | 77267538-9be9-47db-a983-9139de4efe50 192.168.12.0/24  |

Security Group

# nova secgroup-list
+--------------------------------------+---------+-------------+
| Id                                   | Name    | Description |
+--------------------------------------+---------+-------------+
| 319b5bc2-5df2-44c1-b2d9-8d08689e4a8a | default | default     |
+--------------------------------------+---------+-------------+

Flavor

# nova flavor-list
+--------------------------------------+---------------+-----------+------+-----------+------+-------+-------------+-----------+
| ID                                   | Name          | Memory_MB | Disk | Ephemeral | Swap | VCPUs | RXTX_Factor | Is_Public |
+--------------------------------------+---------------+-----------+------+-----------+------+-------+-------------+-----------+
| 1                                    | m1.tiny       | 512       | 1    | 0         |      | 1     | 1.0         | True      |
| 12d7efd2-2d1d-44ec-ad66-ce7ca8927c0b | m1.medium     | 4096      | 0    | 0         |      | 2     | 1.0         | True      |
| 2                                    | m1.small      | 2048      | 20   | 0         |      | 1     | 1.0         | True      |
| 318a3051-4304-4f3a-bda7-6f3a7637152b | m1.nano       | 256       | 1    | 0         |      | 1     | 1.0         | True      |
| 4                                    | m1.large      | 8192      | 80   | 0         |      | 4     | 1.0         | True      |
| 5                                    | m1.xlarge     | 16384     | 160  | 0         |      | 8     | 1.0         | True      |
+--------------------------------------+---------------+-----------+------+-----------+------+-------+-------------+-----------+

Restore from the image(snapshot) (= Create new Nova instance)

# nova boot --flavor m1.nano \
            --image admin_vm01_ss \
            --security-groups default \
            --availability-zone nova \
            --nic net-id=b3fa9d4d-4c21-47f5-be07-cf2ff518035e \
            admin_vm02
+--------------------------------------+------------------------------------------------------+
| Property                             | Value                                                |
+--------------------------------------+------------------------------------------------------+
| OS-DCF:diskConfig                    | MANUAL                                               |
| OS-EXT-AZ:availability_zone          | nova                                                 |
| OS-EXT-SRV-ATTR:host                 | -                                                    |
| OS-EXT-SRV-ATTR:hypervisor_hostname  | -                                                    |
| OS-EXT-SRV-ATTR:instance_name        | instance-00000444                                    |
| OS-EXT-STS:power_state               | 0                                                    |
| OS-EXT-STS:task_state                | scheduling                                           |
| OS-EXT-STS:vm_state                  | building                                             |
| OS-SRV-USG:launched_at               | -                                                    |
| OS-SRV-USG:terminated_at             | -                                                    |
| accessIPv4                           |                                                      |
| accessIPv6                           |                                                      |
| adminPass                            | Df9gLcC7nkHq                                         |
| config_drive                         |                                                      |
| created                              | 2015-02-17T03:02:25Z                                 |
| flavor                               | m1.nano (318a3051-4304-4f3a-bda7-6f3a7637152b)       |
| hostId                               |                                                      |
| id                                   | 94c75110-54a7-408a-b7e6-13b6961617bf                 |
| image                                | admin_vm01_ss (88648405-a9f5-40ae-bfb0-0ff2d7608258) |
| key_name                             | -                                                    |
| metadata                             | {}                                                   |
| name                                 | admin_vm02                                           |
| os-extended-volumes:volumes_attached | []                                                   |
| progress                             | 0                                                    |
| security_groups                      | default                                              |
| status                               | BUILD                                                |
| tenant_id                            | a8085d1871f847bdb906ef4a28d1bd48                     |
| updated                              | 2015-02-17T03:02:25Z                                 |
| user_id                              | a1c2ec19759040e39f219fcf82028bf6                     |
+--------------------------------------+------------------------------------------------------+

Check the restored Nova instance

# nova list
+--------------------------------------+------------+--------+------------+-------------+---------------------+
| ID                                   | Name       | Status | Task State | Power State | Networks            |
+--------------------------------------+------------+--------+------------+-------------+---------------------+
| 7961383e-7528-4e26-8889-ab452bae0e7f | admin_vm01 | ACTIVE | -          | Running     | net04=192.168.12.78 |
| 94c75110-54a7-408a-b7e6-13b6961617bf | admin_vm02 | ACTIVE | -          | Running     | net04=192.168.12.79 |
+--------------------------------------+------------+--------+------------+-------------+---------------------+

Environment

Openstack : Juno
Ceph : Firefly

Reference

Nova Snapshot/Restore
Nova Backup/Restore