Friday, September 28, 2012 posted by John Griffith
Welcome Cinder!!! Six months ago at the OpenStack Folsom Design Summit there were multiple sessions focused on the idea of separating block storage out of Nova. Block storage is an integral component of a cloud infrastructure. In order to accelerate advancement of the block storage service within OpenStack required greater focus, awareness and contribution. In short, it needed its own project. Thanks to a lot of hard work from over 50 contributors, Cinder (aka OpenStack Block Storage) is now a reality.
The birth of a new core OpenStack project is a significant accomplishment. It has been an incredible experience watching this project come to life with everything ranging from the creation in Launchpad, to git repos, Gerrit and Jenkins infrastructure, Devstack, Tempest, etc. A lot of hard work from a lot of people working together made this happen in a very short period of time.
Once all the pieces were in place for Cinder to live on its own, the fun began! Job one was to extract nova-volumes from Nova. This included significant modifications to Nova just to make the extraction possible. Along the way it was imperative to maintain compatibility and NOT impact existing volume API's. In parallel with the Nova work, the process of porting Nova-Volume code into Cinder was moving full speed ahead. Essentially the first month after the Folsom Summit was dedicated to these efforts.
Once we had an independent service, endpoint mappings and a new Cinder client we were ready to roll. While compatibility was a clear priority in this release we also strived for quality improvements and minimally invasive feature additions. Some of the key block storage enhancements included in the Folsom release include:
- A Nova-Volume compatible Block Storage Service
- Updates to all of the back-end storage drivers
- NFS as block storage support
- Improved Boot From Volume with ability to specify image at volume creation
- Ability to create an Image From Volume
- Persistent iSCSI targets
- Resuming interrupted volume operations in case of service shutdown
Along with all the work in Cinder, we also ported every bug fix and feature to Nova-Volume. Why you ask? With Nova-Volume being deprecated we wanted to minimize confusion and make the migration process as easy and painless as possible. We also worked on tools to migrate your existing Nova-Volume related database tables to your new Cinder nodes. The migration tools are included in the cinder-manage utility which can be used to migrate your DB as well as your persistent iSCSI target files. One thing to keep in mind, in order to make this migration as easy and smooth as possible, it's required that you upgrade your existing Nova-Volume install to Folsom before performing the migration to Cinder.
It's an exciting time for Cinder and we are just getting started. There is significant potential for Block Storage in OpenStack. Now that we have the initial release of Cinder stable and ready for use, we can turn our focus to Grizzly. I look forward to discussing new feature additions and improvements we are working on at the OpenStack Summit in two weeks in San Diego. See you there!
-John Griffith, Senior Software Engineer & Cinder PTL