FileDriverSpec
- Launchpad Entry: NovaSpec:filedriver
- Created: 2011-02-08
- Contributors: Christian Berendt
Contents
Summary
Implementation of a file based volume driver to manage images created by and creating with qemu-img, for example on a mounted NFS export.
Release Note
- no code provided for a release at the moment, so no release notes
Rationale
- ??? what should i write here ???
User stories
- often there are existing big filers only accessible per NFS and not per iSCSI
Assumptions
- storage is already mounted on the system, it should not be mounted by the driver
- storage is readable and writable by the nova-volume process
- storage is mounted, readable and writable on all compute nodes
- for example by using NFS or OCFS2
- it's possible to use more than one mountpoint to storage the images
- it's possible to specify the used format
Design
- at the moment "local" storage can only be used by using LVM2
Implementation
- check if the specified storage is correctly mounted and writable before creating a new image
- create a new images with qemu-img
- remove images with rm
- mabye better to use a Python library here
- check needed free storage on the storage with df
- mabye better to use a Python library here
- add a new FLAG to set the default format
- add a new FLAG to specify one or more mountpoints to be used to store new images
- add the possibility to import already created images as a new volume
- useful for migrating and using existing images into/in the cloud
- add the possibility to choose the used format per volume
- add the possibility to choose the used mountpoint per volume
- add the possibility to move one image from a mountpoint to an other one
UI Changes
- add a new list in the dashboard to choose the format to use by newly created volume
Code Changes
- create new method FileDriver() in nova/volume/driver.py implementing the points described unter Implementation
Migration
- I don't know if it's possible at the momentan to use 2 volume drivers in one Nova setup
- if it's possible there has to be implemented a method to migrate from and to migrate to a file image
Test/Demo Plan
This need not be added or completed until the specification is nearing beta.
Unresolved issues
- no implementation at the moment, so there are no unresolved issues
BoF agenda and discussion
- no discussion at the moment