Use snapshots to migrate instances¶

Create a snapshot of the instance¶

1. Shut down the source VM before you take the snapshot to ensure that all data is flushed to disk. If necessary, list the instances to view the instance name:

   $ nova list
   +--------------------------------------+------------+--------+------------------------------+
   | ID                                   | Name       | Status | Networks                     |
   +--------------------------------------+------------+--------+------------------------------+
   | c41f3074-c82a-4837-8673-fa7e9fea7e11 | myInstance | ACTIVE | private=10.0.0.3             |
   +--------------------------------------+------------+--------+------------------------------+
   

2. Use the nova stop command to shut down the instance:

   $ nova stop myInstance
   

3. Use the nova list command to confirm that the instance shows a SHUTOFF status:

   $ nova list
   +--------------------------------------+------------+---------+------------------+
   | ID                                   | Name       | Status  | Networks         |
   +--------------------------------------+------------+---------+------------------+
   | c41f3074-c82a-4837-8673-fa7e9fea7e11 | myInstance | SHUTOFF | private=10.0.0.3 |
   +--------------------------------------+------------+---------+------------------+
   

4. Use the nova image-create command to take a snapshot:

   $ nova image-create --poll myInstance myInstanceSnapshot
   Instance snapshotting... 50% complete
   

5. Use the nova image-list command to check the status until the status is ACTIVE:

   $ nova image-list
   +--------------------------------------+---------------------------------+--------+--------+
   | ID                                   | Name                            | Status | Server |
   +--------------------------------------+---------------------------------+--------+--------+
   | 657ebb01-6fae-47dc-986a-e49c4dd8c433 | cirros-0.3.2-x86_64-uec         | ACTIVE |        |
   | 72074c6d-bf52-4a56-a61c-02a17bf3819b | cirros-0.3.2-x86_64-uec-kernel  | ACTIVE |        |
   | 3c5e5f06-637b-413e-90f6-ca7ed015ec9e | cirros-0.3.2-x86_64-uec-ramdisk | ACTIVE |        |
   | f30b204e-1ce6-40e7-b8d9-b353d4d84e7d | myInstanceSnapshot              | ACTIVE |        |
   +--------------------------------------+---------------------------------+--------+--------+
   

Download the snapshot as an image¶

1. Get the image ID:

   $ nova image-list
   +-------------------+-------------------+--------+--------------------------------------+
   | ID               | Name              | Status | Server                                |
   +-------------------+-------------------+--------+--------------------------------------+
   | f30b204e-1ce6... | myInstanceSnapshot| ACTIVE | c41f3074-c82a-4837-8673-fa7e9fea7e11  |
   +------------------+-------------------+--------+---------------------------------------+
   

2. Download the snapshot by using the image ID that was returned in the previous step:

   $ glance image-download --file snapshot.raw f30b204e-1ce6-40e7-b8d9-b353d4d84e7d
   

   Note

   The glance image-download command requires the image ID and cannot use the image name. Check there is sufficient space on the destination file system for the image file.

3. Make the image available to the new environment, either through HTTP or direct upload to a machine (scp).

Import the snapshot to the new environment¶

In the new project or cloud environment, import the snapshot:

$ glance --os-image-api-version 1 image-create \
  --container-format bare --disk-format qcow2 --copy-from IMAGE_URL

Boot a new instance from the snapshot¶

In the new project or cloud environment, use the snapshot to create the new instance:

$ nova boot --flavor m1.tiny --image myInstanceSnapshot myNewInstance