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<div class="moz-cite-prefix">On 25/08/20 12:05 am, Dmitry Tantsur
wrote:<br>
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cite="mid:CACNgkFydM1fmKZJ4wVwuJz-7aTC5A+NzAVLAgoxH5UaCkK_uwQ@mail.gmail.com">
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<div dir="ltr" class="gmail_attr">On Mon, Aug 24, 2020 at 1:52
PM Sean Mooney <<a href="mailto:smooney@redhat.com"
moz-do-not-send="true">smooney@redhat.com</a>> wrote:<br>
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<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">On Mon, 2020-08-24 at
10:32 +0200, Dmitry Tantsur wrote:<br>
> Hi,<br>
> <br>
> On Mon, Aug 24, 2020 at 10:24 AM Arne Wiebalck <<a
href="mailto:arne.wiebalck@cern.ch" target="_blank"
moz-do-not-send="true">arne.wiebalck@cern.ch</a>><br>
> wrote:<br>
> <br>
> > Hi!<br>
> > <br>
> > CERN's deployment is using the iscsi deploy
interface since we started<br>
> > with Ironic a couple of years ago (and we
installed around 5000 nodes<br>
> > with it by now). The reason we chose it at the
time was simplicity: we<br>
> > did not (and still do not) have a Swift backend to
Glance, and the iscsi<br>
> > interface provided a straightforward alternative.<br>
> > <br>
> > While we have not seen obscure bugs/issues with
it, I can certainly back<br>
> > the scalability issues mentioned by Dmitry: the
tunneling of the images<br>
> > through the controllers can create issues when
deploying hundreds of<br>
> > nodes at the same time. The security of the iscsi
interface is less of a<br>
> > concern in our specific environment.<br>
> > <br>
> > So, why did we not move to direct (yet)? In
addition to the lack of<br>
> > Swift, mostly since iscsi works for us and the
scalability issues were<br>
> > not that much of a burning problem ... so we
focused on other things :)<br>
> > <br>
> > Here are some thoughts/suggestions for this
discussion:<br>
> > <br>
> > How would 'direct' work with other Glance backends
(like Ceph/RBD in our<br>
> > case)? If using direct requires to duplicate
images from Glance to<br>
> > Ironic (or somewhere else) to be served, I think
this would be an<br>
> > argument against deprecating iscsi.<br>
> > <br>
> <br>
> With image_download_source=http ironic will download
the image to the<br>
> conductor to be able serve it to the node. Which is
exactly what the iscsi<br>
> is doing, so not much of a change for you (except for
s/iSCSI/HTTP/ as a<br>
> means of serving the image).<br>
> <br>
> Would it be an option for you to test direct deploy
with<br>
> image_download_source=http?<br>
i think if there is still an option to not force deployemnt
to altere any of there<br>
other sevices this is likely ok but i think the onious
shoudl be on the ironic<br>
and ooo teams to ensure there is an upgrade path for those
useres before this deprecation<br>
becomes a removal without deploying swift or a swift
compatibale api e.g. RadosGW<br>
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<div>Swift is NOT a requirement (nor is RadosGW) when
image_download_source=http is used. Any glance backend (or
no glance at all) will work.<br>
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<p>Even though the TripleO undercloud has swift, I'd be inclined to
do image_download_source=http so that it can scale out to minions,
and so we're not relying on a single-node swift for image serving<br>
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