taikun.cloud

Taikun OCP Guide

Table of Contents

Use snapshots to migrate instances

This guide can be used to migrate an instance between different
clouds.

To use snapshots to migrate instances from OpenStack projects to
clouds, complete these steps.

In the source project:

  1. Create_a_snapshot_of_the_instance
  2. Download_the_snapshot_as_an_image

In the destination project:

  1. Import_the_snapshot_to_the_new_environment
  2. Boot_a_new_instance_from_the_snapshot

Note

Some cloud providers allow only administrators to perform this
task.

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:

    $ openstack server list
    +--------------------------------------+------------+--------+------------------+--------------------+-------------------------+
    | ID                                   | Name       | Status | Networks         | Image              | Flavor                  |
    +--------------------------------------+------------+--------+------------------+--------------------+-------------------------+
    | d0d1b7d9-a6a5-41d3-96ab-07975aadd7fb | myInstance | ACTIVE | private=10.0.0.3 | ubuntu-16.04-amd64 | general.micro.tmp.linux |
    +--------------------------------------+------------+--------+------------------+--------------------+-------------------------+
  2. Use the openstack server stop command to shut down the
    instance:

    $ openstack server stop myInstance
  3. Use the openstack server list command to confirm that the
    instance shows a SHUTOFF status:

    $ openstack server list
    +--------------------------------------+------------+---------+------------------+--------------------+-------------------------+
    | ID                                   | Name       | Status  | Networks         | Image              | Flavor                  |
    +--------------------------------------+------------+---------+------------------+--------------------+-------------------------+
    | d0d1b7d9-a6a5-41d3-96ab-07975aadd7fb | myInstance | SHUTOFF | private=10.0.0.3 | ubuntu-16.04-amd64 | general.micro.tmp.linux |
    +--------------------------------------+------------+---------+------------------+--------------------+-------------------------+
  4. Use the openstack server image create command to take a
    snapshot:

    $ openstack server image create --name myInstanceSnapshot myInstance

    If snapshot operations routinely fail because the user token times
    out while uploading a large disk image, consider configuring nova to use
    service user tokens <service_user_token>.

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

    $ openstack image list
    +--------------------------------------+---------------------------+--------+
    | ID                                   | Name                      | Status |
    +--------------------------------------+---------------------------+--------+
    | ab567a44-b670-4d22-8ead-80050dfcd280 | myInstanceSnapshot        | active |
    +--------------------------------------+---------------------------+--------+

Download the snapshot as an
image

  1. Get the image ID:

    $ openstack image list
    +--------------------------------------+---------------------------+--------+
    | ID                                   | Name                      | Status |
    +--------------------------------------+---------------------------+--------+
    | ab567a44-b670-4d22-8ead-80050dfcd280 | myInstanceSnapshot        | active |
    +--------------------------------------+---------------------------+--------+
  2. Download the snapshot by using the image ID that was returned in
    the previous step:

    $ openstack image save --file snapshot.raw ab567a44-b670-4d22-8ead-80050dfcd280

    Note

    The openstack image save 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:

$ openstack image create --container-format bare --disk-format qcow2 \
  --file snapshot.raw myInstanceSnapshot

Boot a new instance from
the snapshot

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

$ openstack server create --flavor m1.tiny --image myInstanceSnapshot myNewInstance