Crate snapshot of an instance

Taking an instance snapshot can be useful if you want to keep a certain version of an instance.
For example: to relaunch an instance from a previous version or migrate an instance to another project.

Create snapshot

Before taking a snapshot, please make sure the instance is stopped.

Taking snapshot by using

$ openstack server image create <instance> --name myInstanceSnapshot

This creates an image named myInstanceSnapshot.

$ openstack image list
+------------+---------------------------------+--------+
| ID         | Name                            | Status |
+------------+---------------------------------+--------+
| id-image-1 | cirros-0.3.5-x86_64-uec         | active |
| id-image-2 | cirros-0.3.5-x86_64-uec-kernel  | active |
| id-image-3 | cirros-0.3.5-x86_64-uec-ramdisk | active |
| id-image-4 | myInstanceSnapshot              | active |
+------------+---------------------------------+--------+

Use case

Launch instance from snapshot

You can launch a new instance using a snapshot for the image parameter.

$ openstack server create --flavor <flavor> --image <snapshot> <instance>

Migrate to another project

Migrate an instance to another OpenStack project requires three steps:

1. download snapshot as image
2. import the image into the new project
3. in the new project, launch new instance from imported snapshot as an image