Openstack Magnum uses Cinder to provision storage for kubernetes cluster. As you can read here:
In some use cases, data read/written by a container needs to persist
so that it can be accessed later. To persist the data, a Cinder volume
with a filesystem on it can be mounted on a host and be made available
to the container, then be unmounted when the container exits.
...
Kubernetes allows a previously created Cinder block to be mounted to a
pod and this is done by specifying the block ID in the pod YAML file.
When the pod is scheduled on a node, Kubernetes will interface with
Cinder to request the volume to be mounted on this node, then
Kubernetes will launch the Docker container with the proper options to
make the filesystem on the Cinder volume accessible to the container
in the pod. When the pod exits, Kubernetes will again send a request
to Cinder to unmount the volume’s filesystem, making it available to
be mounted on other nodes.
Its usage is described in this section of the documentation.
If setting up Cinder seems like too much overhead, you can use local volume type which allows to use local storage device such as a disk, partition or directory already mounted on a worker node's filesystem.
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
