Difference between revisions of "Xenapi-sm-volume-driver"
| Line 6: | Line 6: | ||
== Summary == | == Summary == | ||
| − | Design and implement a new driver for Nova-Volume, based on XenAPI Storage Manager | + | Design and implement a new driver for Nova-Volume, based on XenAPI Storage Manager. This will provide basic storage functionality (like volume creation, and destruction) on a number of different storage back-ends, but it will enable the capability of using more sophisticated storage back-ends for operations like cloning/snapshotting etc. To have an idea of the benefits of using XenAPI SM to provide back-end storage services, the list below shows some of the storage plugins already supported in [[XenServer]]/XCP: |
* NFS VHD: SR plugin which stores disks as VHD files on a remote NFS filesystem | * NFS VHD: SR plugin which stores disks as VHD files on a remote NFS filesystem | ||
| Line 23: | Line 23: | ||
== Rationale == | == Rationale == | ||
| − | This becomes premium value for service provider clouds or may become differentiator for enterprise private clouds. | + | This new driver will sit along side drivers already developed like AoE, iSCSI and SAN (both running on commodity boxes running Linux). However, the latter is slightly different as it will still run on commodity hardware, but it access remote controllers on SAN hardware by some protocol like SSH, CLI or custom API. This is clearly undesirable because every time there is a need to support new hardware, a new driver must be designed and developed. The adoption of XenAPI SM will unleash a number of storage back-end that are abstracted with a common API. Moreover, this becomes premium value for service provider clouds or may become differentiator for enterprise private clouds. |
== User stories == | == User stories == | ||
| Line 35: | Line 35: | ||
== Design == | == Design == | ||
| − | + | The steps involved in order to support this activity are: | |
| + | |||
| + | * | ||
== Implementation == | == Implementation == | ||
| − | |||
| − | |||
=== UI Changes === | === UI Changes === | ||
| Line 46: | Line 46: | ||
=== Code Changes === | === Code Changes === | ||
| + | |||
Most of the changes will be on top of the current code, however there is a possibility where some changes to Nova-Volume Manager are required to make it more general and accommodate the use of XenAPI SM. More when the actual implementation starts. | Most of the changes will be on top of the current code, however there is a possibility where some changes to Nova-Volume Manager are required to make it more general and accommodate the use of XenAPI SM. More when the actual implementation starts. | ||
=== Migration === | === Migration === | ||
| + | |||
This new driver may require changes to the database schema, more to follow once the actual implementation starts. However procedures to migrate DB schema will be provided. | This new driver may require changes to the database schema, more to follow once the actual implementation starts. However procedures to migrate DB schema will be provided. | ||
| Line 57: | Line 59: | ||
== Unresolved issues == | == Unresolved issues == | ||
| − | None | + | None at the time of writing |
== BoF agenda and discussion == | == BoF agenda and discussion == | ||
| − | None | + | None at the time of writing |
---- | ---- | ||
[[Category:Spec]] | [[Category:Spec]] | ||
Revision as of 19:02, 10 March 2011
- Launchpad Entry: NovaSpec:xenapi-sm-support
- Created: 1 February 2011
- Contributors: Armando Migliaccio
Summary
Design and implement a new driver for Nova-Volume, based on XenAPI Storage Manager. This will provide basic storage functionality (like volume creation, and destruction) on a number of different storage back-ends, but it will enable the capability of using more sophisticated storage back-ends for operations like cloning/snapshotting etc. To have an idea of the benefits of using XenAPI SM to provide back-end storage services, the list below shows some of the storage plugins already supported in XenServer/XCP:
- NFS VHD: SR plugin which stores disks as VHD files on a remote NFS filesystem
- Local VHD on LVM: SR plugin which represents disks as VHD disks on Logical Volumes within a locally-attached Volume Group
- HBA LUN-per-VDI driver: SR plugin which represents LUNs as VDIs sourced by hardware HBA adapters, e.g. hardware-based iSCSI or FC support
- NetApp: SR driver for mapping of LUNs to VDIs on a NETAPP server, providing use of fast snapshot and clone features on the filer
- LVHD over FC: SR plugin which represents disks as VHDs on Logical Volumes within a Volume Group created on an HBA LUN, e.g. hardware-based iSCSI or FC support
- iSCSI: Base ISCSI SR driver, provides a LUN-per-VDI. Does not support creation of VDIs but accesses existing LUNs on a target.
- LVHD over iSCSI: SR plugin which represents disks as Logical Volumes within a Volume Group created on an iSCSI LUN
- EqualLogic: SR driver for mapping of LUNs to VDIs on a EQUALLOGIC array group, providing use of fast snapshot and clone features on the array
Release Note
No direct impact on user consuming the external HTTP API services. This blueprint enables the use of several storage back-ends by writing a single nova-volume driver, rather than several ones, as many as the specific storage back-ends required to be supported are needed. In due course, leveraging capabilities of specific back-ends, will enable operations like volume snapshotting, cloning, etc. that can be exposed via official API.
Rationale
This new driver will sit along side drivers already developed like AoE, iSCSI and SAN (both running on commodity boxes running Linux). However, the latter is slightly different as it will still run on commodity hardware, but it access remote controllers on SAN hardware by some protocol like SSH, CLI or custom API. This is clearly undesirable because every time there is a need to support new hardware, a new driver must be designed and developed. The adoption of XenAPI SM will unleash a number of storage back-end that are abstracted with a common API. Moreover, this becomes premium value for service provider clouds or may become differentiator for enterprise private clouds.
User stories
TBD
Assumptions
For the design and implementation of the new Nova-Volume driver, XenAPI for XenServer/XCP is going to be used.
Design
The steps involved in order to support this activity are:
Implementation
UI Changes
There should be no visible changes to the end users, all this work will be behind the API servers.
Code Changes
Most of the changes will be on top of the current code, however there is a possibility where some changes to Nova-Volume Manager are required to make it more general and accommodate the use of XenAPI SM. More when the actual implementation starts.
Migration
This new driver may require changes to the database schema, more to follow once the actual implementation starts. However procedures to migrate DB schema will be provided.
Test/Demo Plan
Unit tests will be provided as code is developed.
Unresolved issues
None at the time of writing
BoF agenda and discussion
None at the time of writing
