1. Storage as a Service and
OpenStack Cinder
Sajid Akhtar
TME, Open source Cloud Solution
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2. Storage as a Service
• CAPEX to OPEX based business model.
• Manage storage by well-defined set of remotely accessible APIs
• Abstracts the actual storage implementation
• This service offers specialized functions: DR, backup, document sharing,
etc.
Using Storage as a Service
• Object
• Block
• File
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3. What Is OpenStack?
Global collaboration
• Developers
• Cloud computing technologists
Open source cloud computing platform
• Public clouds
• Private clouds
Solutions for all types of clouds
• Simple to implement
• Massively scalable
• Feature rich
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4. Quick OpenStack Overview
An Open Source Cloud Computing Platform
• Provides for all types of clouds
– Simple
– Scalable
– Feature rich
• Total cloud infrastructure solution
– Combination of interrelated projects
• Open source software around 3 years old
• OpenStack Foundation established 2012
• Over 700+ organizations contributing to development
• Established and growing number of production deployments
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5. OpenStack Services diagram
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6. Type of storage available on OpenStack
Ephemeral(On-instance) :
-Used for running Operating System and scratch space
-Persists until VM is terminated
-Access associated with a VM
-Implemented as a filesystem underlying OpenStack Compute
-Administrator configures size setting, based on flavors
-Example: 10GB first disk, 30GB/core second disk
For desktop user PC's internal disk drives are ephemeral; persistent
storage can be considered similar to an external USB drive.
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7. OpenStack Object Storage (Swift)
What Is It?
• Object Storage is ideal for cost effective, scale-out storage. It provides a
fully distributed, API-accessible storage platform that can be integrated
directly into applications or used for backup, archiving and data retention.
• Highly available & distributed object / blob store(known as a binary large
object, collection of binary data stored as a single entity in a database
management system. Blobs are typically images, audio or other
multimedia objects)
– Ring architecture
• In production today
– Rackspace’s Cloud Files, Internap, Wikimedia Foundation
• Architectural overview:
– http://swift.openstack.org/overview_architecture.html
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8. Swift (Contd.)
• OpenStack Object Storage can function on its own. The Object Storage
(swift) product can be used independently of the Compute (nova) product.
• Not used like a traditional hard drive.The access to it is API-based (and the
API uses http). It allows you to store or retrieve files (but not mount
directories like a fileserver).
• Used for storing virtual machine images and data
• Persists until deleted
• Available from anywhere
• Easily scalable for future growth
Glance: The OpenStack Image Service is used to manage the virtual
machine images in an OpenStack cluster, not store them. Instead, it provides
an abstraction to different methods for storage - a bridge to the storage, not
the storage itself.
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9. OpenStack Block Storage (Cinder)
What Is It?
• Block Storage allows block devices to be exposed and connected to
compute instances for expanded storage, better performance and
integration with enterprise storage platforms.
• OpenStack provides persistent block level storage devices for use
with OpenStack compute instances. Can be exposed to applications
as well.
• The block storage system manages the creation, attaching and
detaching of the block devices to servers. Block storage volumes are
fully integrated into OpenStack Compute and the Dashboard
allowing for cloud users to manage their own storage needs.
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10. Cinder (Contd.)
• Cinder separates out the persistent block storage functionality that was
previously part of Openstack Compute into it's own service. The
OpenStack Block Storage API allows for manipulation of volumes, volume
types (similar to compute flavors) and volume snapshots.
• This is block storage (or volumes) and currently there are blueprints for
filesystems like NFS or CIFS share
• Used for adding additional persistent storage to a virtual machine (VM)
• Persists until deleted
• Access associated with a VM
• Mounted via OpenStack Block-Storage controlled protocol (for example,
iSCSI)
• Sizings based on need
• Example: 1TB "extra hard drive"
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11. Block Storage Capabilities
• The block storage system manages the creation, attaching and detaching
of the block devices to servers. Block storage volumes are fully integrated
into OpenStack Compute and the Dashboard allowing for cloud users to
manage their own storage needs.
• Block storage is appropriate for performance sensitive scenarios such as
database storage, expandable file systems, or providing a server with
access to raw block level storage.
• Snapshot management provides powerful functionality for backing up
data stored on block storage volumes. Snapshots can be restored or used
to create a new block storage volume.
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12. Cinder call flow
Database Cinder API Queue
C - scheduler
Cinder Vol Cinder Vol
Cinder Vol
iSCSI NFS
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13. Cinder (Contd.)
• cinder-api accepts API requests and routes them to cinder-volume for
action.
• cinder-volume acts upon the requests by reading or writing to the Cinder
database to maintain state, interacting with other processes (like cinder-
scheduler) through a message queue and directly upon block storage
providing hardware or software. It can interact with a variety of storage
providers through a driver architecture. Currently, there are drivers for
IBM, SolidFire, NetApp, Nexenta, Zadara, linux iSCSI and other storage
providers.
• Much like nova-scheduler, the cinder-scheduler daemon picks the optimal
block storage provider node to create the volume on.
• Cinder deployments will also make use of a messaging queue to route
information between the cinder processes as well as a database to store
volume state.
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14. Minimum Driver Features
• In order to be accepted for a given milestone release, Cinder driver must
implement the following features
• Grizzly Release:
– Volume Create/Delete
– Volume Attach/Detach
– Snapshot Create/Delete
– Create Volume from Snapshot
– Get Volume Stats (driver_version/ free_capacity_gb
/reserved_percentage /storage_protocol /total_capacity_gb
/vendor_name /volume_backend_name )
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15. Quick references for Cinder
• Source code: https://github.com/openstack/cinder
• Bug tracker: https://bugs.launchpad.net/cinder
• Blueprints: https://blueprints.launchpad.net/cinder
• Developer doc: http://docs.openstack.org/developer/cinder/
• API complete reference: http://api.openstack.org/api-ref.html
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16. How to start contributing ?
• Become a member and create profile : https://www.openstack.org/join
• Sign User license
• Create launchpad account and review the projects
.
• Openstack Wiki : http://wiki.openstack.org/
• Join IRC channel and register to OpenStack mailing list.
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