So are we going to see you tomorrow at BoA? How is it going? Denise
> On Nov 17, 2016, at 7:55 PM, Subhendu Ghosh <sghosh...@gmail.com> wrote: > > Assuming cloud-init can also select the storage or is that too late in the > process? > > >> On Nov 16, 2016 15:58, "Vivek Goyal" <vgo...@redhat.com> wrote: >> On Wed, Nov 16, 2016 at 03:19:06PM -0500, Stephen Gallagher wrote: >> > On 11/16/2016 03:09 PM, Vivek Goyal wrote: >> > > On Wed, Nov 16, 2016 at 03:01:06PM -0500, Stephen Gallagher wrote: >> > >> On 11/16/2016 02:56 PM, Vivek Goyal wrote: >> > >>> On Wed, Nov 16, 2016 at 02:49:25PM -0500, Stephen Gallagher wrote: >> > >>>> On 11/16/2016 02:40 PM, Vivek Goyal wrote: >> > >>>>> On Wed, Nov 16, 2016 at 02:32:46PM -0500, Daniel J Walsh wrote: >> > >>>>>> We would like to change the docker container storage to default to >> > >>>>>> Overlayfs2 in Fedora 26. But we have a problem on Atomic Host and >> > >>>>>> Fedora Server distributions. >> > >>>>>> >> > >>>>>> >> > >>>>>> Currently docker-storage-setup defaults to devicemapper and is hard >> > >>>>>> coded to setup a thinpool of 40% of remaining disk. Otherwise it >> > >>>>>> sets >> > >>>>>> up loopback devices on the root file system. Devicemapper is nice >> > >>>>>> since it works with thinpools and can automatically expand the >> > >>>>>> storage >> > >>>>>> if the disk space is getting used up. >> > >>>>>> >> > >>>>>> Moving to Overlay, we can more easily use the root file system >> > >>>>>> directly, >> > >>>>>> which would be fine for Fedora Workstation. We want to preserve >> > >>>>>> the use >> > >>>>>> of the remaining storage for Overlay on AH and Fedora Server, since >> > >>>>>> this would give a user flexibility to switch back to using >> > >>>>>> devicemapper >> > >>>>>> if they had problems with the Overlay driver. >> > >>>>> >> > >>>>> And being able to do so basically involves following. >> > >>>>> >> > >>>>> - docker-storage-setup creates a logical volume from free space >> > >>>>> - Creates a filesystem on that logical volume >> > >>>>> - Mounts that logical volume on the directory which docker is going >> > >>>>> to >> > >>>>> use. >> > >>>>> >> > >>>>> mount /dev/docker-vg/foo /var/lib/docker/ >> > >>>>> >> > >>>>> - Now when docker users overlay2 graph driver, all the images, >> > >>>>> containers >> > >>>>> and associated metadata will be stored outside the root filesystem >> > >>>>> and >> > >>>>> onto /dev/docker-vg/foo logical volume. >> > >>>>> >> > >>>>>> We can not as easily >> > >>>>>> support the expanding disk for Overlay since we will not use using >> > >>>>>> thinpool. >> > >>>>> >> > >>>>>> >> > >>>>>> We have looked at options to hard code OverlayFS with the defaults, >> > >>>>> >> > >>>>> If we always mount /var/lib/docker on on /dev/vg/foo for overlay2 >> > >>>>> driver >> > >>>>> this will be a regression w.r.t current behavior. So I would not >> > >>>>> recommend changing current behavior. I think this should be an >> > >>>>> opt-in. >> > >>>>> We are working on provide a config knob to elect this behavior and >> > >>>>> atomic host and fedora server will have to opt-in somehow. >> > >>>>> >> > >>>>> I think it will be easy for atomic host as they already drop >> > >>>>> something >> > >>>>> in /etc/sysconfig/docker-storage-setup. Not sure how fedora server >> > >>>>> variant will do it. >> > >>>>> >> > >>>> >> > >>>> >> > >>>> Today, Fedora Server relies on whatever is the default for >> > >>>> docker-storage-setup. >> > >>>> We just tell Anaconda to reserve up to 15GiB by default for the / >> > >>>> partition and >> > >>>> then it puts all remaining free space (on drives selected to be used >> > >>>> by >> > >>>> Anaconda) into a single logical volume with no partitions. >> > >>>> >> > >>>> It's a very easy thing for us to drop a different config file for >> > >>>> docker-storage-setup into place for Server. So if that's all we need >> > >>>> to do, let >> > >>>> me know and I'll work it up. >> > >>> >> > >>> Ok, that sounds good. We are working on providing a knob to opt-in new >> > >>> behavior. I think all you have to drop in config file will be something >> > >>> like. >> > >>> >> > >>> /etc/sysconfig/docker-storage-setup >> > >>> >> > >>> STORAGE_DRIVER=overlay2 >> > >>> YET_TO_BE_NAMED_OPTION=VAL >> > >>> >> > >>> So upstream default will continue to be devicemapper. We will have to >> > >>> modify fedora workstation, fedora server and atomic host infrastructure >> > >>> to opt-in for overlay2. >> > >>> >> > >> >> > >> Why exactly does this need to be opt-in? Why wouldn't we just change >> > >> the default >> > >> on Fedora Server to use overlay2 instead of devicemapper? >> > >> >> > >> I think I'm missing some key part of the problem here. >> > > >> > > I mean it will be devicemapper in upstream project. And distributions >> > > will >> > > have to opt-in for overlay2. >> > > >> > > And I think one reason being that rhel uses same git tree and we don't >> > > want to switch to overlay2 by default for rhel yet. >> > > >> > > overlay2 will be an experiment on fedora first as default and if it works >> > > well, then change default upstream too. >> > >> > OK, when you said "opt-in", I was assuming you meant that from the user's >> > perspective (as in having the user make an explicit choice). What you >> > meant was >> > that Server would carry a different default from the upstream project. >> > That's >> > easy enough to accomplish (we can do the same for Atomic as well). >> > >> > The packaging guidelines for this are here: >> > https://fedoraproject.org/wiki/Packaging:Per-Product_Configuration >> > >> > Of course, that's only necessary if we want Server (and Atomic) to differ >> > from >> > Workstation and/or non-productized Fedora. If they're all going to switch >> > to >> > overlay2, then it's just a trivial matter. >> >> I think all are going to switch to overlay2 by default. But there will >> be on difference. Fedora workstation will like to have its overaly2 >> setup on top of rootfs. While Fedora Server and Atomic Host will like >> to carve out extra logical volume from free space and setup overlay2 >> on top of that. >> >> So there will be total of two config options. One will be same in all >> 3 variants. While second one will be used only by server and atomic >> host variants. >> >> /me goes to read per product configuraiton link now. >> >> Vivek >> _______________________________________________ >> devel mailing list -- devel@lists.fedoraproject.org >> To unsubscribe send an email to devel-le...@lists.fedoraproject.org > _______________________________________________ > devel mailing list -- devel@lists.fedoraproject.org > To unsubscribe send an email to devel-le...@lists.fedoraproject.org
_______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org
