Changes between Version 10 and Version 11 of Internal/VMHostSetup


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Timestamp:
May 4, 2012, 10:20:24 PM (12 years ago)
Author:
ssugrim
Comment:

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  • Internal/VMHostSetup

    v10 v11  
    144144    ovs_version: "1.2.2.10448"
    145145}}}
    146 Note that the taps are distributed according to which vlan/subnet they are supposed to belong to. I also switch from e1000 emulation to virtio, because its supposed to preform better. The big discovery with this setup was in how to invoke the kvm. Originally I replicated the -net... flag and started the vm. This works but it bonds the two interfaces together. Packets from one virtual interface show up on both bridges and go out of both cards. The reason this happens is a missing vlan keyword in the -net flag. This vlan keyword has nothing to do with vlan tagging for packets egress from the virtual interfaces. It's purely about the internal representation of the interfaces and the internal switching that qemu/kvm does. Specifying different vlan flags for the different interfaces and their respective taps, fixed the bonding problem. Packets were not only present on the proper bridge. I also had to modify all the scripting infrastructure to reflect this change. Instead of a single ovs-ifup/down script, there are now two(ovs-ifup-br0 and ovs-ifup-br1), one for each bridge. There are also now two scripts for starting vms depending on whether you want 1 or two interfaces.
     146Note that the taps are distributed according to which vlan/subnet they are supposed to belong to. I also switch from e1000 emulation to virtio, because its supposed to preform better. The big discovery with this setup was in how to invoke the kvm. Originally I replicated the -net... flag and started the vm. This works but it bonds the two interfaces together. Packets from one virtual interface show up on both bridges and go out of both cards. The reason this happens is a missing vlan keyword in the -net flag. This vlan keyword has nothing to do with vlan tagging for packets egress from the virtual interfaces. It's purely about the internal representation of the interfaces and the internal switching that qemu/kvm does. Specifying different vlan flags for the different interfaces and their respective taps, fixed the bonding problem. Packets were not only present on the proper bridge. This is documented [http://publib.boulder.ibm.com/infocenter/lnxinfo/v3r0m0/index.jsp?topic=%2Fliaat%2Fliaatbptap.htm here]. See attached PDF  (since this site is some what flaky) [[attachment:KVM-MULTI-NETWORK.pdf]].
     147
     148I also had to modify all the scripting infrastructure to reflect this change. Instead of a single ovs-ifup/down script, there are now two(ovs-ifup-br0 and ovs-ifup-br1), one for each bridge. There are also now two scripts for starting vms depending on whether you want 1 or two interfaces.
    147149{{{
    148150Single interface command string
     
    204206
    205207refrences:
     208 * http://publib.boulder.ibm.com/infocenter/lnxinfo/v3r0m0/index.jsp?topic=%2Fliaat%2Fliaatbptap.htm
    206209 * http://translate.googleusercontent.com/translate_c?hl=en&ie=UTF8&rurl=translate.google.de&sl=de&tl=en&u=http://qemu-buch.de/de/index.php/QEMU-KVM-Buch/_Inhaltsverzeichnis&usg=ALkJrhir9hvb8x9SA1RJNnNapZstHXVYGg
    207210 * http://en.wikibooks.org/wiki/QEMU