[Engine-devel] Proposal for support ISO domain on other types of file based storage.

[Ayal Baron]

----- Original Message -----
> Mark Wu :
> > On Sun 17 Mar 2013 10:12:55 PM CST, Ayal Baron wrote:
> >>
> >>
> >> ----- Original Message -----
> >>>
> >>> Hi guys,
> >>>
> >>> Currently, ISO domain is only supported on NFS storage. It could
> >>> improve the ease of use if it allows other types
> >>> of file based storage to store ISO images. After an
> >>> investigation, I
> >>> found there's not any restriction on this idea.
> >>> So the whole work is removing the limitation on engine side. That
> >>> means engine should allow ISO domain could
> >>> have different storage type from the data center it's attached,
> >>> like
> >>> what we do with nfs ISO domain in SAN DC.
> >>>
> >>> I start this idea with localfs. I know local storage can't be
> >>> seen in
> >>> cluster level. But it also provides a choice if no
> >>> NFS available. VMs can be created on the host which has the ISO
> >>> repo,
> >>> and then be migrated to any other host in the cluster.
> >>> I have done the initial patches: allow creation ISO domain on
> >>> localfs
> >>> [1] and support import ISO domain on localfs [2]
> >>> I don't have much experience in java/j2ee/web development and
> >>> engine
> >>> architecture. The patches just work for me.
> >>> I am not sure if it will bring some potential problems. So any
> >>> feedback on the patch or the idea will be appreciated very much.
> >>
> >> Haven't looked at the patches yet, but wrt the idea, I agree on
> >> the
> >> need (being able to attach ISOs from anywhere and not just nfs)
> >> but I
> >> think the way to do this should be by getting rid of the ISO
> >> domain
> >> type altogether.
> >
> > I think ISO domain on localfs is useful for a simple setup or demo,
> > such as oVirt all-in-one.
> >
> >> Basically what we need is:
> >> 1. a way to connect to file based storage (let's leave block aside
> >> for now) - this already exists via the connectStorageServer verb
> >> 2. a way to list and present a file system tree in gui (give an
> >> arbitrary path to vdsm and list content) and possibly filter
> >> results
> >> by type (vfd, iso) - does not exist today. Possibly some security
> >> aspects here that need hashing out.
> >> 3. a way to specify a path to a file when attaching an iso/vfd to
> >> a
> >> VM - this is the way it works today
> >>
> >> This would devoid the need for isoUploader and allow users to
> >> simply
> >> manage an nfs export with files.
> >> Next step would be to make connectStorageServer support httpfs [1]
> >> and then we'd be able to mount ISOs directly over http (hopefully
> >> this would be sufficient to support ISOs stored on S3, swift,
> >> glance,
> >> etc).
> >
> > Actually, we could use the qemu curl backend image support
> > directly.
> > That means we don't need mount the place storing ISO images. We can
> > just maintain a list of ISO image with its link, which could be
> > http,
> > ftp and ssh.
> 
> That will be fine to start a VM on a existing extern ISO image. I
> also
> would like to maintain a ISO image cache on the local host to avoid
> to
> re-streaming the ISO image from the ISO image repositories every
> time.
> That will be helpful for people who is suffered from the network
> bottleneck.

We have a similar requirement for glance support (not limited to ISOs, rather to all read-only images) so that should be tackled with a broader solution.

> 
> >
> >>
> >> [1] http://httpfs.sourceforge.net/
> >>
> >>>
> >>>
> >>> Mark.
> >>>
> >>> [1] http://gerrit.ovirt.org/#/c/12687/
> >>> [2] http://gerrit.ovirt.org/#/c/12916/
> >>>
> >>> _______________________________________________
> >>> Engine-devel mailing list
> >>> Engine-devel at ovirt.org
> >>> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >>>
> >>
> >
> >
> > _______________________________________________
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> > Engine-devel at ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/engine-devel
> >
> 
> 
> --
> ---
> 舒明 Shu Ming
> Open Virtualization Engineerning; CSTL, IBM Corp.
> Tel: 86-10-82451626  Tieline: 9051626 E-mail: shuming at cn.ibm.com or
> shuming at linux.vnet.ibm.com
> Address: 3/F Ring Building, ZhongGuanCun Software Park, Haidian
> District, Beijing 100193, PRC
> 
> 
>