On Mon, Mar 3, 2014 at 8:13 PM, Zhangleiqiang <zhangleiqi...@huawei.com> wrote: >> >> This sounds like ephemeral storage plus snapshots. You build a base image, >> snapshot it then boot from the snapshot. > > > Non-persistent storage/disk is useful for sandbox-like environment, and this > feature has already exists in VMWare ESX from version 4.1. The implementation > of ESX is the same as what you said, boot from snapshot of the disk/volume, > but it will also *automatically* delete the transient snapshot after the > instance reboots or shutdowns. I think the whole procedure may be controlled > by OpenStack other than user's manual operations.
Why reboot an instance? What is wrong with deleting it and create a new one? > > As far as I know, libvirt already defines the corresponding <transient> > element in domain xml for non-persistent disk ( [1] ), but it cannot specify > the location of the transient snapshot. Although qemu-kvm has provided > support for this feature by the "-snapshot" command argument, which will > create the transient snapshot under /tmp directory, the qemu driver of > libvirt don't support <transient> element currently. > > I think the steps of creating and deleting transient snapshot may be better > to done by Nova/Cinder other than waiting for the <transient> support added > to libvirt, as the location of transient snapshot should specified by Nova. > > > [1] http://libvirt.org/formatdomain.html#elementsDisks > ---------- > zhangleiqiang > > Best Regards > > >> -----Original Message----- >> From: Joe Gordon [mailto:joe.gord...@gmail.com] >> Sent: Tuesday, March 04, 2014 11:26 AM >> To: OpenStack Development Mailing List (not for usage questions) >> Cc: Luohao (brian) >> Subject: Re: [openstack-dev] [nova][cinder] non-persistent storage(after >> stopping VM, data will be rollback automatically), do you think we shoud >> introduce this feature? >> >> On Mon, Mar 3, 2014 at 6:00 PM, Yuzhou (C) <vitas.yuz...@huawei.com> >> wrote: >> > Hi stackers, >> > >> > As far as I know ,there are two types of storage used by VM in openstack: >> Ephemeral Storage and Persistent Storage. >> > Data on ephemeral storage ceases to exist when the instance it is >> > associated >> with is terminated. Rebooting the VM or restarting the host server, however, >> will not destroy ephemeral data. >> > Persistent storage means that the storage resource outlives any other >> resource and is always available, regardless of the state of a running >> instance. >> > >> > There is a use case that maybe need a new type of storage, maybe we can >> call it non-persistent storage . >> > The use case is that VMs are assigned to the public ephemerally in public >> areas. >> > After the VM is used, new data on storage of VM ceases to exist when the >> instance it is associated with is stopped. >> > It means stop the VM, Non-persistent storage used by VM will be rollback >> automatically. >> > >> > Is there any other suggestions? Or any BPs about this use case? >> > >> >> This sounds like ephemeral storage plus snapshots. You build a base image, >> snapshot it then boot from the snapshot. >> >> > Thanks! >> > >> > Zhou Yu >> > >> > _______________________________________________ >> > OpenStack-dev mailing list >> > OpenStack-dev@lists.openstack.org >> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> >> _______________________________________________ >> OpenStack-dev mailing list >> OpenStack-dev@lists.openstack.org >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > _______________________________________________ > OpenStack-dev mailing list > OpenStack-dev@lists.openstack.org > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
