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| − | | + | #REDIRECT [[Manila]] |
| − | * '''Launchpad Entry''': cinder-protocol-enhancements
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| − | * '''Created''': 29 Sep 2012
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| − | * '''Contributors''': Robert Esker, Ben Swartzlander
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| − | | |
| − | == Introduction ==
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| − | | |
| − | This document is intended to vet a concept and establish a vision for extending Cinder capabilities. More detailed blueprints (in Launchpad) and further detail in this specification will follow as necessary.
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| − | | |
| − | == Glossary ==
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| − | | |
| − | Please note the following [[OpenStack]] standard definition of terms (this glossary is adapted from a separate blueprint and is included here for consistency and to eliminate conflict over term definitions):
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| − | * disk: block-based storage read and written by a virtual machine
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| − | * ephemeral disk: a disk that is stored locally on the hypervisor host; will be discarded if the VM is shut down and on failures
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| − | * disk image: a sequence of bytes managed by Glance, copied to local storage by Nova to create an ephemeral disk
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| − | * volume: persistent (non-ephemeral) block-based storage. Note that this definition may (and often does) conflict with vendor-specific definitions.
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| − | * block device mapping: means by which a VM launched by Nova determines disks are attached to it, including both ephemeral disks and persistent volumes
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| − | * file system: a system for organizing and storing data in directories and files. A shared file system provides (and arbitrates) concurrent access from multiple clients generally over IP networks and via established protocols.
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| − | * NFS: [http://en.wikipedia.org/wiki/Network_File_System Network File System]
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| − | * CIFS: [http://en.wikipedia.org/wiki/Server_Message_Block Common Internet File System]
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| − | | |
| − | == Background ==
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| − | | |
| − | === Cinder characteristics ===
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| − | * The [[OpenStack]] Cinder project separates the former nova-volume into an independent service for Folsom and beyond.
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| − | * Instances can be created from ephemeral disks or volumes presently
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| − | * Creating an ephemeral disk is done by Nova downloading the specified disk image from Glance over HTTP, writing it to local (to the hypervisor) storage
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| − | * Ad hoc requests for storage, whether by running instances or outside of the Nova context can be accommodated either programmatically against the Cinder API or via the python-cinderclient tool.
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| − | * Cinder, in the initial form and as a legacy of nova-volume, provides a block only construct.
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| − | | |
| − | == High-level proposal ==
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| − | | |
| − | Concordant with the transition from nova-volume to Cinder, the opportunity to define a broader vision for storage provisioning in [[OpenStack]] exists. An expanded vision for Cinder is both appropriate for an independent project / service in [[OpenStack]] and is also timely given a variety of user driven requirements advocating for expanded capabilities. We propose and intend to act to evolve Cinder as the canonical storage provisioning control plane in [[OpenStack]] independent of storage protocol type (whether block or file). This proposal and associated blueprints intend to, in phases, accommodate file-based storage as well. Please note that object storage is not considered in scope given well established API and mechanisms (i.e. Swift). This blueprint should be treated as an overarching / umbrella design document with separate blueprints defined for each of the phases and to also account for "whole experience" interaction.
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| − | | |
| − | == Blueprints ==
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| − | | |
| − | The master blueprint is here: [https://blueprints.launchpad.net/cinder/+spec/cinder-protocol-enhancements Cinder Protocol Enhancements]
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| − | | |
| − | === 1) File-Based Volume Driver ===
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| − | | |
| − | Implementation of a Cinder file-based volume driver. This makes use of files as virtual block devices for mounted file systems already present at the hypervisor. The hypervisor would still present the file into the instance as a block device.
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| − | [https://blueprints.launchpad.net/cinder/+spec/nfs-files-as-virtual-block-devices Allow the use of NFS files as virtual block devices]
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| − | Note: the above provides generic NFS support as a reference implementation
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| − | [https://blueprints.launchpad.net/cinder/+spec/netapp-nfs-cinder-driver NetApp-NFS Driver for Cinder]
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| − | | |
| − | === 2) Extension of the Cinder API ===
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| − | | |
| − | Extension of the [http://api.openstack.org Cinder API] to accommodate:
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| − | | |
| − | * Creation of file system shares (e.g. the create API needs to support a "protocol" & a permissions "mask" and "ownership" parameters)
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| − | * Coordination of mounting file system shares
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| − | * Creation & deletion of snapshots & clones
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| − | * List, show, provide and deny access to file system shares
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| − | * Unmounting file systems shares
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| − | * Deletion of file systems shares
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| − | * Snapshot, list snapshots, and delete snapshots of file system shares
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| − | The API description is here: [[CinderProtocolEnhancementsAPI|Cinder Protocol Enhancements API Proposal]]
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| − | | |
| − | === 3) Extended API Reference Driver ===
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| − | Creation of a reference Cinder driver for shared file system use under the proposed expanded API. As an example, a [[NetApp]] driver for this would be able to advertise, accept, and respond to requests for NFSv3, NFSv4, NFSv4.1 (w/ pNFS), & contemporary CIFS / SMB protocols (eg versions 2, 2.1, 3). Additional modification of python-cinderclient will be necessary to provide for the expanded array of request parameters.
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| − | | |
| − | === 4) Control of NAS Storage Mounting from Cinder ===
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| − | Proposal for handling injection / updates of mounts to instantiated guests operating in the Nova context. A listener / agent that could either be interacted directly or more likely poll or receive updates from instance metadata changes would represent one possible solution.
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| − | | |
| − | === 5) Quantum Support ===
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| − | Full consideration for cross-instance network encapsulation as part of a Quantum & Keystone integrated security model.
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| − | | |
| − | ----
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| − | [[Category:Spec]]
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