[one-users] virtio-blk-data-plane and x-data-plane=on

Thu Sep 5 03:25:59 PDT 2013

Hi

I haven't tried this myself either, but if there is such an improvement we
could add a hint at the KVM driver documentation.

I've a concern about the first sentence of the post:

"Data plane is suitable for LVM or raw image file configurations where live
migration and advanced block features are not needed."

So, are we missing then live-migration? have you tried it?

On Thu, Sep 5, 2013 at 12:02 PM, Vladislav Gorbunov <vadikgo at gmail.com>wrote:

> It works with:
> DISK     = [ driver = "raw" , cache = "none", io = "native"]
> and on RedHat/CentOS kvm only.
>
> 2013/9/1 Valentin Bud <valentin.bud at gmail.com>:
> > Hi Erico,
> >
> > This is the first time I hear about virtio-blk-data-plane. Thank you for
> the
> > info, looks like this feature brings notable IO improvements.
> >
> > You can try to use the RAW Section [1] to pass special attributes to the
> > underlying hypervisor.
> > I have found a blog post [2] in which there is a method to enable
> > virtio-blk-data-plane using the libvirt XML. The RAW section DATA gets
> > passed to libvirt in XML format.
> >
> > I think the following could work:
> >
> > RAW = [
> >   TYPE="kvm",
> >   DATA="<qemu:commandline><qemu:arg value='-set'/><qemu:arg
> > value='device.virtio-disk0.scsi=off'/></qemu:commandline><!--
> config-wce=off
> > is not needed in RHEL 6.4 --><qemu:commandline><qemu:arg
> > value='-set'/><qemu:arg
> >
> value='device.virtio-disk0.config-wce=off'/></qemu:commandline><qemu:commandline<qemu:arg
> > value='-set'/><qemu:arg
> > value='device.virtio-disk0.x-data-plane=on'></qemu:commandline>"
> > ]
> >
> > I don't have a test machine around and I would to hear back from you if
> it
> > works or not.
> >
> > [1]: http://opennebula.org/documentation:rel4.2:template#raw_section
> > [2]:
> >
> http://blog.vmsplice.net/2013/03/new-in-qemu-14-high-performance-virtio.html
> >
> > Health and Goodwill,
> >
> >
> > On Sat, Aug 31, 2013 at 11:01 PM, Erico Augusto Cavalcanti Guedes
> > <eacg at cin.ufpe.br> wrote:
> >>
> >> Hello,
> >>
> >> on [1], page 10, section 2.3 - KVM Configuration: "To achieve the best
> >> possible I/O rates for the KVM guest, the virtio-blk-data-plane feature
> was
> >> enabled for each LUN (a disk or partition) that was passed from the
> host to
> >> the guest. To enable virtio-blk-data-plane for a LUN being passed to the
> >> guest, the x-data-plane=on option was added for that LUN in the qemu-kvm
> >> command line used to set up the guest. For example:
> >> /usr/libexec/qemu-kvm -drive
> >> if=none,id=drive0,cache=none,aio=native,format=raw,file=<disk or
> partition>
> >> -device virtio-blk-pci,drive=drive0,scsi=off,x-data-plane=on
> >> "
> >> I'll be grateful if you can help me with the following question:
> >> How to customize -device virtio-blk-pci parameter during OpenNebula VM
> >> initialization to insert x-data-plane=on on it?
> >>
> >> My VM Template:
> >> CONTEXT=[NETWORK="YES",SSH_PUBLIC_KEY="$USER[SSH_PUBLIC_KEY]"]
> >> CPU="1"
> >>
> >>
> DISK=[AIO="native",BUS="virtio",CACHE="none",DEV_PREFIX="vd",FORMAT="raw",IMAGE_ID="1"]
> >> GRAPHICS=[LISTEN="0.0.0.0",TYPE="VNC"]
> >> MEMORY="256"
> >> NIC=[NETWORK_ID="0"]
> >> OS=[ARCH="i686",BOOT="hd"]
> >>
> >> KVM process on node:
> >> /usr/bin/kvm -S -M pc-i440fx-1.6 -cpu qemu32 -enable-kvm -m 256 -smp
> >> 1,sockets=1,cores=1,threads=1 -name one-27
> >> -uuid c014337c-5255-e983-862e-b744f889aa49 -no-user-config -nodefaults
> >> -chardev
> >>
> socket,id=charmonitor,path=/var/lib/libvirt/qemu/one-27.monitor,server,nowait
> >> -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc
> >> -no-shutdown-boot c
> >> -drive
> >>
> file=/srv/cloud/one/var//datastores/0/27/disk.0,if=none,id=drive-virtio-disk0,format=raw,cache=none
> >> -device
> >>
> virtio-blk-pci,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0
> >> -drive
> >>
> file=/srv/cloud/one/var//datastores/0/27/disk.1,if=none,media=cdrom,id=drive-ide0-0-0,readonly=on,format=raw
> >> -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0
> >> -netdev tap,fd=22,id=hostnet0
> >> -device
> >>
> virtio-net-pci,netdev=hostnet0,id=net0,mac=02:00:c0:a8:0f:6e,bus=pci.0,addr=0x3
> >> -usb -vnc 0.0.0.0:27 -vga cirrus -device
> >> virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5
> >>
> >> I'm running ONE 4.2 on Debian 7.1 x86_64, kernel 3.2.0-4-amd64, with
> >> customized qemu-1.6(compiled by myself to support
> virtio-blk-data-plane) to
> >> enable virtio-blk-data-plane, with Debian 7.1 i386 VMs.
> >>
> >> Thanks in advance,
> >>
> >> Erico.
> >>
> >> [1]
> >>
> ftp://public.dhe.ibm.com/linux/pdfs/KVM_Virtualized_IO_Performance_Paper_v2.pdf
> >>
> >> _______________________________________________
> >> Users mailing list
> >> Users at lists.opennebula.org
> >> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
> >>
> >
> >
> >
> > --
> > Valentin Bud
> > http://databus.pro | valentin at databus.pro
> >
> > _______________________________________________
> > Users mailing list
> > Users at lists.opennebula.org
> > http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
> >
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-- 
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OpenNebula - The Open Source Solution for Data Center Virtualization
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