1. OpenStack Cinder
Renuka Apte – Citrix Systems

2. Overview
• What is Cinder
• Who’s Involved
• API
• nova-volume attach/detach now & ahead
• Boot from volume now & ahead
• Current Status
• What’s left & timeline
• How to get involved

3. What is Cinder
• Service that was previously nova-volume
• REST based API
• Why?
• Increasing Complexity in nova-volume
• Scheduler
• Multiple volume drivers working together
• Interactions with other components, e.g. glance

4. Who’s Involved
• SolidFire
• John Griffith
• Rackspace
• Vish, Jesse Andrews, Anthony Young, Nirmal Ranganathan…
• HP
• Tim Reddin, Duncan Thomas
• Ceph
• Josh Durgin
• Zadara
• Vladimir Popovski
• NetApp
• Rob Esker
• Citrix
• Renuka Apte

5. REST API
• What’s supported today
• create
• delete
• list
• show
• Extensions (to come)
• attach
• detach
• reserve_volume
• unreserve_volume
• initialize_connection
• terminate_connection

6. Current Flow of Attach/Detach
Calls
• user attach
• compute.api  reserve_volume (sets attaching state)
casts to manager
• compute.manager  initialize_connection (gets connection info)
• compute.manager  attach (sets instance_id and attach state
• (unreserve_volume called on error)
• user detach
• compute.api  casts to manager
• compute.manager  terminate_connection
• compute_manager  detach (removes instance_id and attach
state)
• (unreserve_volume called during terminate)

7. Future Flow (tentative)
• user attach
• compute_api  initialize_connection (sets instance_id, attaching
state, gets connection info)
• starts greenthread (optionally, could be sync as well)
• makes call to manager passing down connection info
• attach (sets instance_id and attach state)
• creates bdm data
• user detach
• compute_api  starts greenthread (optionally, could be sync as well)
• detach (sets detaching state)
• makes call to manager
• terminate_connection (clears instance_id and attach state)
• destroys bdm data

8. Boot from Volume, now
• Current state
• nova boot [--flavor <flavor>] [--image <image>] [--
block_device_mapping <dev_name=mapping>] <name>
• The format of mapping is
<dev_name=<id>:<type>:<size(GB)>:<delete_on_terminate>
• Current way of creating bootable volumes
• get the image from url or template from swift
• create a nova-volume
• attach it to a running instance
• cp/dd

9. Boot from Volume, ahead
• Considerations
• Who should create bootable volume?
• Should cinder be a client to glance or replicate functionality for
streaming templates?
• Boot from Volume
• Create a bootable Volume
• Option #1: Create Volume from an Image (or snapshot?)
• cinder create-volume-from-image --image_id=[image_id]
• Option #2: Mark an existing volume as bootable
• Launch an instance from that Volume
• nova boot --from_volume=[vol_id]

10. Current Status
• Use cinder to create/delete/list/show volumes
• python-cinderclient works
• Runs against nova-volume and cinder
• Supports create/delete/list/show
• Can point devstack to install cinder
• create/delete volumes
• QA
• Jenkins, smokestack on checkins
• pep8, unit tests and hacking checks

11. In the Pipeline
• Folsom-2
• Volume decoupling
• API extensions
• attach
• detach
• reserve_volume
• unreserve_volume
• initialize_connection
• terminate_connection
• Separate volume api
• Further up
• Boot from volume

12. Incubation
• Normal process
• couple of releases
• acceptance by community
• contributions
• Exception for Cinder
• already an OpenStack project
• nova-volume is reasonably mature and reviewed

13. Try it out
• Pull devstack
• git clone https://github.com/openstack-dev/devstack.git
• cd devstack
• git review –d 7042
• Edit localrc
• In ENABLED_SERVICES, replace n-vol (if it exists, else add) cinder
• Also add c-api, c-vol, c-sch
• Run stack.sh

14. Getting Involved
• Reviews
• Feedback
• Feature priorities
• Resources:
• http://etherpad.openstack.org/cinder-worksheet
• Progress, status, updates
• Repo: https://github.com/openstack/cinder/
• Blueprints:
• https://blueprints.launchpad.net/nova/+spec/volume-decoupling
• https://blueprints.launchpad.net/cinder
• Mailing list:
• openstack@lists.launchpad.net with [Openstack][Cinder] on subject line
• Meetings:
• Wednesdays at 16:00 UTC