Open Stack

On Mar 10, 2014 12:29 PM, "Jay Pipes" <jaypipes at gmail.com> wrote:
>
> On Mon, 2014-03-10 at 12:13 -0400, Shawn Hartsock wrote:
> > We have very strong interest in pursing this feature in the VMware
> > driver as well. I would like to see the revert instance feature
> > implemented at least.
> >
> > When I used to work in multi-discipline roles involving operations it
> > would be common for us to snapshot a vm, run through an upgrade
> > process, then revert if something did not upgrade smoothly. This
> > ability alone can be exceedingly valuable in long-lived virtual
> > machines.
> >
> > I also have some comments from parties interested in refactoring how
> > the VMware drivers handle snapshots but I'm not certain how much that
> > plays into this "live snapshot" discussion.
>
> I think the reason that there isn't much interest in doing this kind of
> thing is because the worldview that VMs are pets is antithetical to the
> worldview that VMs are cattle, and Nova tends to favor the latter (where
> DRS/DPM on vSphere tends to favor the former).
>
> There's nothing about your scenario above of being able to "revert" an
> instance to a particular state that isn't possible with today's Nova.
> Snapshotting an instance, doing an upgrade of software on the instance,
> and then restoring from the snapshot if something went wrong (reverting)
> is already fully possible to do with the regular Nova snapshot and
> restore operations. The only difference is that the "live-snapshot"
> stuff would include saving the memory view of a VM in addition to its
> disk state. And that, at least in my opinion, is only needed when you
> are treating VMs like pets and not cattle.

++, well said.

>
> Best,
> -jay
>
> > On Mon, Mar 10, 2014 at 12:04 AM, Bohai (ricky) <bohai at huawei.com>
wrote:
> > >> -----Original Message-----
> > >> From: Alex Xu [mailto:xuhj at linux.vnet.ibm.com]
> > >> Sent: Sunday, March 09, 2014 10:04 PM
> > >> To: OpenStack Development Mailing List (not for usage questions)
> > >> Subject: Re: [openstack-dev] [nova] a question about instance
snapshot
> > >>
> > >> Hi, Jeremy, the discussion at here
> > >>
http://lists.openstack.org/pipermail/openstack-dev/2013-August/013688.html
> > >>
> > >
> > > I have a great interest in the topic too.
> > > I read the link you provided, and there is a little confusion for me.
> > > I agree with the security consideration in the discussion and memory
snapshot can't be used for the cloning instance easily.
> > >
> > > But I think it's safe for the using for Instance revert.
> > > And revert the instance to a checkpoint is valuable for the user.
> > > Why we didn't use it for instance revert in the first step?
> > >
> > > Best regards to you.
> > > Ricky
> > >
> > >> Thanks
> > >> Alex
> > >> On 2014年03月07日 10:29, Liuji (Jeremy) wrote:
> > >> > Hi, all
> > >> >
> > >> > Current openstack seems not support to snapshot instance with
memory and
> > >> dev states.
> > >> > I searched the blueprint and found two relational blueprint like
below.
> > >> > But these blueprint failed to get in the branch.
> > >> >
> > >> > [1]: https://blueprints.launchpad.net/nova/+spec/live-snapshots
> > >> > [2]: https://blueprints.launchpad.net/nova/+spec/live-snapshot-vms
> > >> >
> > >> > In the blueprint[1], there is a comment,"
> > >> > We discussed this pretty extensively on the mailing list and in a
design
> > >> summit session.
> > >> > The consensus is that this is not a feature we would like to have
in nova.
> > >> --russellb "
> > >> > But I can't find the discuss mail about it. I hope to know why we
think so ?
> > >> > Without memory snapshot, we can't to provide the feature for user
to revert
> > >> a instance to a checkpoint.
> > >> >
> > >> > Anyone who knows the history can help me or give me a hint how to
find the
> > >> discuss mail?
> > >> >
> > >> > I am a newbie for openstack and I apologize if I am missing
something very
> > >> obvious.
> > >> >
> > >> >
> > >> > Thanks,
> > >> > Jeremy Liu
> > >> >
> > >> >
> > >> > _______________________________________________
> > >> > OpenStack-dev mailing list
> > >> > OpenStack-dev at lists.openstack.org
> > >> > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
> > >> >
> > >> >
> > >> >
> > >>
> > >>
> > >> _______________________________________________
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> > >> OpenStack-dev at lists.openstack.org
> > >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
> > > _______________________________________________
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> > > OpenStack-dev at lists.openstack.org
> > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
> >
> >
> >
>
>
>
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