Add cloning via PVC annotation #183
Conversation
This patch enables provisioning new volumes as a clone of an existing PVC. To
request a clone, the user should add a clone request annotation to the PVC:
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: clone-claim
annotations:
k8s.io/CloneRequest: default/source-pvc
The provisioner will locate the indicated PVC and determine the underlying
associated cinder volume ID. The provisioner will use this ID as the
source-vol-id parameter when provisioning the new volume resulting in a clone
at the storage level.
Cloning will only work if the cinder backend supports "smart-cloning". This
means that the clone will complete without the need for cinder to perform a
bit-for-bit copy using the host. Because of this, the cinder provisioner will
not attempt to clone unless the associated storage class contains the
parameter: "smartclone" to indicate that volumes provisioned from this storage
class can be cloned correctly.
If the provisioner was able to clone the volume it will apply the
'k8s.io/CloneOf' annotation to the PVC.
Signed-off-by: Adam Litke <alitke@redhat.com>
k8s-ci-robot
added
cncf-cla: yes
|
Build succeeded.
|
|
/cc @j-griffith |
|
Build succeeded.
|
|
Build succeeded.
|
|
Build succeeded.
|
|
Build succeeded.
|
|
Build succeeded.
|
|
Build succeeded.
|
|
Build succeeded.
|
|
Build succeeded.
|
|
Build succeeded.
|
|
/cc @hogepodge |
|
/ok-to-test |
k8s-ci-robot
removed
the
needs-ok-to-test
|
if the cinder backend supports "smart-cloning" - how I can see does our cinder backend support this? Is this using basically volume clone command? |
|
@zetaab The short answer is "depends on the configuration". I define "smart-cloning" as the ability to provision a new volume clone utilizing exclusively the storage backend. When a source volume id is passed into the create verb cinder will request a clone from the backend storage if supported. Otherwise, cinder will perform a host-assisted clone. Host assisted clone is also needed when cloning across volume types. Cinder host-assisted clone will obviously not work well in a kubernetes context so we want to avoid this. This is why this patch requires the smartclone: true parameter to be added to the storage class being serviced by the provisioner to indicate that volumes provisioned in this storage class can be smart-cloned. |
|
/approve @aglitke please add some notes from here to the docs/ |
k8s-ci-robot
added
the
lgtm
|
[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: dims The full list of commands accepted by this bot can be found here. The pull request process is described here
Needs approval from an approver in each of these files:
Approvers can indicate their approval by writing |
k8s-ci-robot
added
the
approved
Add cloning via PVC annotation
This PR enables provisioning new volumes as a clone of an existing PVC. To
request a clone, the user should add a clone request annotation to the PVC:
The provisioner will locate the indicated PVC and determine the underlying
associated cinder volume ID. The provisioner will use this ID as the
source-vol-id parameter when provisioning the new volume resulting in a clone
at the storage level.
Cloning will only work if the cinder backend supports "smart-cloning". This
means that the clone will complete without the need for cinder to perform a
bit-for-bit copy using the host. Because of this, the cinder provisioner will
not attempt to clone unless the associated storage class contains the
parameter: "smartclone" to indicate that volumes provisioned from this storage
class can be cloned correctly.
If the provisioner was able to clone the volume it will apply the
'k8s.io/CloneOf' annotation to the PVC.