On Fri, Feb 26, 2016 at 12:47 PM, Sean McGinnis <sean.mcgin...@gmx.com> wrote:
> On Fri, Feb 26, 2016 at 06:11:15PM +0000, Srinivas Sakhamuri wrote: > > I want to confirm the correct work flow for detaching a volume, Both nova > > and cinder (unpublished, available through cinder.volumes.detach) > provides > > detach volume API. Only nova seems to have correct work flow in terms of > > detaching a volume i.e. > > 1) detaches the volume from the VM (libvirt.volume_detach) > > 2) Informs Cinder to do Cinder-side detach > > 3) delete BlockDeviceMapping from Nova DB > > > > On the other hand cinder just modifies cinder DB entries and let's the > > driver handle the detaching the volume. No API call to nova to let it > know > > about the volume detaching. > > > > - Does that mean nova is the only work flow to use to correctly detach a > > volume from instance? > > - And cinder detach API serves only to cleanup internal state in the DB > and > > cinder driver? > > I guess it depends on what you are trying to accomplish. If a volume is > being used by nova, then the nova APIs are the correct ones to use to > have it fully detached from the host and cleaned up. > > Internally, Nova calls the Cinder APIs to perform the storage > management. > > If you are just looking to perform storage management, for example > with bare metal and not using Nova, then you would call the > Cinder APIs. > > So to answer your first question of whether the nova API is the correct > way to detach a volume from an instance - yes. > > Sean > > > > > TIA > > Srini > > > > __________________________________________________________________________ > > OpenStack Development Mailing List (not for usage questions) > > Unsubscribe: > openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > Maybe this will help https://review.openstack.org/#/c/285471/ Additionally I've been trying to point out lately that a Volume should be just a "thing" or resource and it's up to consumers of volumes to manage connections (attach/detach) appropriately.
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