This is an overview Cinder as of the Grizzly release. These slides were presented at the OpenStack Atlanta Meetup. Thanks to Avishay Traegar for letting me steal bullet points from his slides.

1. KIDS
ON
THE
BLOCK
NEW
THE
presented by mike perez

2. MIKE
PEREZ
senior developer for DreamHost
cinder core developer

3. WHAT
http://www.flickr.com/photos/neilhinchley/294337822/
• project exists since Folsom
release, spun off Nova-volume
• cinder manages block storage
• not object storage
• not file level storage
• volumes attach toVM Instances
• boot from volume
• volumes have a lifecycle
independent ofVM instance

4. VOLUME
TYPES•Admin can create tiers of storage. e.g. two LVM
backends, one with SSD’s and the other with HDD’s.
•Users can specify a tier they want when creating a
volume.

5. ARCHITECTURAL
OVERVIEW
Cinder Client
Cinder API
CinderVolume Cinder BackupCinder Scheduler
SQL DB
AMPQAMPQ
AMPQ

6. CINDER
API
•Volume create/delete/list/show
•Create from image, snapshot
•Snapshot create/delete/list/show
•Backups create/restore/list/delete/show
•Volume attach/detach (called by Nova)
•Volume types (more later)
•Quotas

7. CINDER
SCHEDULER•Chooses which back-end to place a new volume on
•Configurable plugins for schedulers
•Filter scheduler has plugins for filters and weights: chance, simple and filter.
•Filter scheduler Flow Example:
•Starts with list of all back-ends
•Filters according to capabilities
•Drivers report capabilities and state (e.g., free space)
•Default filters
•Volume types
•Sorts according to weights e.g., available free space
•Returns best candidate

8. CINDER
VOLUME•Drivers: Called by Manager, contains back-end-specific code
to communicate with various storage types (e.g., Linux LVM,
storage controllers from various vendors, distributed file
systems, etc.)
•Admin can run multiple cinder-volume instances, each with
its own configuration file describing settings and the storage
back-end
•As of Grizzly, one cinder-volume instance can manage
multiple back-ends
•Each back-end driver is generally configured to interact with
one storage pool
•Multi-threading

9. CINDER
BACKUP•A backup is an archived copy of aVolume stored in a
object store.
•A backup is just the data that was written, unlike a
snapshot which is the entire block.

10. HIGH
LEVEL
Nova Cinder
VM Instance
LinuxVolume
Manager
KVM
ISCSI
Initiator
Legend
Persistent Volume Data
Persistent Volume Control
/dev/hda
/dev/vda
ISCSI
Initiator

11. ATTACH
THAT
• Nova calls Cinder via its API, passing connection information.
e.g., host name, iSCSI initiator name, FC WWPNs
• Cinder API passes message to Cinder Volume.
• Manager does initial error checking and calls volume driver.
• Volume driver does any necessary preparation to allow the connection.
e.g., give the nova host permissions to access the volume.
• Volume driver returns connection information, which is passed to Nova.
e.g., iSCSI iqn and portal, FC WWPN.
• Nova creates the connection to the storage using the returned information.
• Nova passes the volume device/file to the hypervisor.
VOLUME

12. THE
GRID

13. DRIVER
REQUIREMENTS
•Volume Create/Delete
•Volume Attach/Detach
•Snapshot Create/Delete
•CreateVolume from Snapshot
•GetVolume Stats
•Copy Image toVolume
•CopyVolume to Image
•CloneVolume

14. CURRENT
DRIVERS
•Coraid (AoE)
•EMCVMAX/VNX (iSCSI)
•GlusterFS (GlusterFS)
•HP 3PAR (iSCSI/FC)
•HP LeftHand (iSCSI)
•Huawei T-series/Dorado (iSCSI)
•IBM Storwize family/SVC
(iSCSI/FC)
•IBM XIV (iSCSI), LVM (iSCSI)
•NetApp (iSCSI/NFS)
•Nexenta (iSCSI)
•NFS (NFS)
•RBD (Ceph)
•Scality SOFS (scality)
•Sheepdog (sheepdog)
•Solaris (iSCSI)
•SolidFire (iSCSI)
•Windows Server 2012 (iSCSI)
•Zadara (iSCSI)

15. HAVANA
BOUNDGeneral Features
•Code cleanup and reorganization
•Attach volume to multiple hosts
•Read-only volumes
•Disk encryption
•FC SAN Zone / Access Control
management
•Transfer volume ownership
•Volume Migration
•Work towards locality between
instances and volumes
•State machine
•Volume rate limiting
New Drivers:
•IBM GPFS
•IBM zVM
•EMC Isilon (iSCSI)
•Local disk partitions
•Hitachi HUS (DF850) (iSCSI)
•Dell Equalogic
•Violin Memory v6000 (iSCSI)

16. THANK
YOU!•Get started with Cinder:
•https://wiki.openstack.org/wiki/Cinder
•Source Code:
•http://github.com/openstack/cinder
•REST API Docs:
•http://docs.openstack.org/api/openstack-block-
storage/2.0
•Thanks Avishay Traeger from IBM for letting me
copy things out of his slides.
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