[Gluster-users] Possible to use libgfapi with libvirt in CentOS 6.5?

Sat Mar 29 01:16:07 UTC 2014

Hi all,

I just installed a Fedora 20 test host, and after struggling with
dependencies I'm happy to report that everything works perfectly. I'm not
relying on the virt-manager gui at all, and from what I'm reading,
currently libvirt cannot start an image from gluster via libgfapi anyway(?).

For various reasons I don't wish to use Fedora in my production
environment, so until the SIG group works their magic, if there is a way to
compile the latest sources for qemu and libvirt on CentOS or Debian, I'll
be in business.

The performance difference between libgfapi and fuse is like night and day,
very impressive. I never want to have to go back to running VM's over fuse
again.

Thanks again to everyone,
David

On Fri, Mar 28, 2014 at 10:47 AM, Lalatendu Mohanty <lmohanty at redhat.com>wrote:

>  On 03/28/2014 07:26 PM, SATHEESARAN wrote:
>
> On 03/28/2014 05:37 PM, Dave Christianson wrote:
>
>   I've come across individual posts from people who supposedly have done
> this in CentOS6.5. Basically, all that is shown in the posts is the XML
> file generated, no mention of *how* that file is generated. Virt-manager
> has no provision for attaching directly to the gluster volume except as a
> mount. Neither virt-manager nor virt-install recognize the gluster:// type.
>
> Yes, even I was frustrated at this. There seems no way to utilize the
> image file using libgfapi.
> As Harsha mentioned in his earlier thread, libvirt is yet to expose this.
> I have already raised a bug regarding this,
> https://bugzilla.redhat.com/show_bug.cgi?id=1017308
>
>  Supposedly earlier versions of RHEL used qemu-kvm as a wrapper for
> qemu-system-x86_64, however in 6.5 qemu-kvm is its own binary. Qemu-kvm
> also doesn't recognize the gluster:// type.
>
> With RHEL 6.5 / Centos 6.5 you can use, "/usr/libexec/qemu-kvm"
> This was the command that I used to make use of VM Images using libgfapi
> in RHEL 6.5
> >> /usr/libexec/qemu-kvm  -drive file=gluster://
> 10.70.37.87/testvol/test.img,if=none,id=drive-virtio-disk0,format=qcow2,cache=none,werror=stop,rerror=stop,aio=threads-device
> virtio-blk-pci,scsi=off,bus=pci.0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=0
>
> The above worked for me.
> If I am not wrong, the libvirt in RHEL 7 supports glusterfs's libgfapi way
> of access mechanism.
>
>
> Sas,
>
> What about Fedora 20? Fedora 20 should have all the latest RPMs , so it
> should  have required patches in libvirt too.
>
> -Lala
>
>
>
>
>  Debian and Ubuntu supposedly have the newer versions of gluster and
> qemu/libvirt availabe (ppa's?). Maybe I'll test Wheezy...
>
>  Red Hat seems content to do their own thing. Although the verisons of
> libvirt and qemu are older, libgfapi is supposed to have been backported.
> It's a shame that full functionality is not included. It's mindboggling
> seeing that Red Hat owns glusterfs, you would think full support for the
> backend would have been included in their product. If it is, as you say,
> that RH includes this functionality only to RHN subscribers and is not made
> available downstream to CentOS/SL, and unless I can find a repository with
> the latest full versions of qemu & libvirt, then CentOS simply will not
> work.
>
>
> On Fri, Mar 28, 2014 at 3:13 AM, Harshavardhana <harsha at harshavardhana.net
> > wrote:
>
>> Virt-manager / libvirt is yet to expose perhaps this functionality -
>> but as far as i remember libvirt should be doing this as a
>> pass-through for the URL's which have been passed  as
>> "<schema>://<server>/<volname>"
>>
>> Does libvirt 'invoke' fuse when passed "gluster://" schema?
>>
>> On Thu, Mar 27, 2014 at 5:34 PM, Dave Christianson
>> <davidchristianson3 at gmail.com> wrote:
>> > Good Evening,
>> >
>> > I have read that libgfapi has been backported to qemu-kvm in RHEL 6.5
>> (and
>> > by virtue CentOS and SL). However I am unable to figure out how to
>> actually
>> > make it work as described. Virt-manager still only seems to support
>> > glusterfs volumes via fuse.
>> >
>> > I can use qemu-img to create a disk image on
>> gluster://<server>/<Volume>.
>> > But virt-manager can only use it from a fuse mounted fileshare. There
>> seems
>> > to be no ability to attach in virt-manager directly to the image on
>> > glusterfs using libgfapi.
>> >
>> > All documents I've found describe the use of the command
>> > "qemu-system-x86_64," however that command does not exist in CentOS 6.5.
>> > That appears to be the only way to start the domain using libgfapi. So
>> > basically, I can create an image via libgfapi but cannot do anything
>> useful
>> > with it.
>> >
>> > Should I be able to do this? If so, what's the procedure? Or is
>> CentOS/RHEL
>> > 6.5 just not fully integrated? I really want to be able to use libgfapi
>> and
>> > avoid the performance penalty of fuse. Should I just grab & compile the
>> > latest verisons of libvirt and qemu-kvm?
>> >
>> > _______________________________________________
>> > Gluster-users mailing list
>> > Gluster-users at gluster.org
>> > http://supercolony.gluster.org/mailman/listinfo/gluster-users
>>
>>
>>
>> --
>> Religious confuse piety with mere ritual, the virtuous confuse
>> regulation with outcomes
>>
>
>
>
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