On Thu, Jan 2, 2014 at 3:38 PM, Changqian Zuo <dummyhacke...@gmail.com> wrote: > Hi, > > First time mailing to a list. > > I'm trying to add a RBD volume snapshot rollback operation to Cinder. > I've just got through WSGI part of Cinder API code and have read some > pieces of Cinder Volume. Now there is not much time for me to complete > the whole code base (with Ceph driver) very carefully, I need some > advice. > > Is adding a Extension Controller the most suitable way to do this? How > to deal with snapshot and volume state transformation, would it affect > other part of Cinder codes? What parts of Cinder codes I should pay > special attention? > > Many thanks. > > Some background information: > > We're planning to use Cinder bootable volume (Ceph RBD as backend) as > instance root disk in my company's OpenStack environment. Creating a > volume snapshot from image, and then use this snapshot to spawn instance > root volumes.
>From your description, it seemed that you can use rbd as nova backend directly. nova.conf: libvirt_image_type='rbd' more options can be find at nova/virt/libvirt/imagebackend.py > > To backup volume state, I've thought of Cinder-Backup service (still > need to add a in-use backup for Cinder), but it takes too much space (a > 80G volume would take at least 248G space for base backup image with x3 > Ceph replication ratio). The other way is volume snapshot, but in this > case when restoring volume data, I have to create a new volume from > snapshot, destroy the original instance (there's no API to change a > instance's bootable volume), and create a new instance from new volume. > > The old volume can not be removed, for a snapshot is referencing to it > (the snapshot must be kept). If I do this again and again, there would > be many snapshots referencing to many different volumes, and I have to > keep these volumes (not used elsewhere), which is a mess. > > > > _______________________________________________ > Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack > Post to : openstack@lists.openstack.org > Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack -- Best Regards, Wheat _______________________________________________ Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack Post to : openstack@lists.openstack.org Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack
