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<p class="MsoNormal">Hi list,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">I'm working under CentOS 6.4 + Havana.<o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white;max-width: 45em;orphans: auto;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">I'm trying to enable jumbo frames for Openstack instances.<o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white;max-width: 45em;orphans: auto;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">I'm using libvirt_vif_driver=nova.virt.libvirt.vif.LibvirtHybridOVSBridgeDriver in nova.conf</span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333">.<o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white;max-width: 45em;orphans: auto;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">I noticed there is a parameter in plugins/openvswitch/ovs_neutron_plugin.ini I can use, so I set it to:<br>
veth_mtu = 9000<o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white;max-width: 45em;orphans: auto;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">And, it works fine :<br>
ip link |grep 9000<br>
6: eth4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc mq state UP qlen 1000<br>
263: phy-br-eth4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc pfifo_fast state UP qlen 1000<br>
264: int-br-eth4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc pfifo_fast state UP qlen 1000<br>
10: br-eth4: <BROADCAST,UP,LOWER_UP> mtu 9000 qdisc noqueue state UNKNOWN<o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white;max-width: 45em;orphans: auto;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">But, after the instance booted, all ports used for the instance are still MTU=1500:<br>
ip link |grep df6a018a-0d<br>
273: qbrdf6a018a-0d: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN<br>
274: qvodf6a018a-0d: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000<br>
275: qvbdf6a018a-0d: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000<br>
276: tapdf6a018a-0d: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500<o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white;max-width: 45em;orphans: auto;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">So I have to<br>
1. find the exact ports using by the instance<br>
2. change their MTU one by one<br>
3. </span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333">enter</span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333"> the instance to change the MTU</span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333">
by hand <o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white;max-width: 45em;orphans: auto;widows: auto;-webkit-text-stroke-width: 0px;word-spacing:0px">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">Is there</span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333"> a</span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333"> way that can make sure
after the instance booted, all ports have MTU=9000 </span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333">without change by hand
</span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333">??</span><span style="font-size:9.0pt;font-family:"Courier New";color:#333333"><o:p></o:p></span></p>
<p style="mso-margin-top-alt:0in;margin-right:0in;margin-bottom:.2in;margin-left:0in;line-height:13.5pt;background:white">
<span style="font-size:9.0pt;font-family:"Courier New";color:#333333">Thanks.<br>
-chen<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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