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<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif; "><div>Hi,</div><div>There was a bug and that code was only fixed last week. Please see <a href="https://review.openstack.org/#/c/62221">https://review.openstack.org/#/c/62221</a>/</div><div>Thanks</div><div>Gary</div><div><br></div><span id="OLK_SRC_BODY_SECTION"><div style="font-family:Calibri; font-size:11pt; text-align:left; color:black; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt"><span style="font-weight:bold">From: </span> <Li>, Chen <<a href="mailto:chen.li@intel.com">chen.li@intel.com</a>><br><span style="font-weight:bold">Date: </span> Monday, January 27, 2014 9:39 AM<br><span style="font-weight:bold">To: </span> "<a href="mailto:openstack@lists.openstack.org">openstack@lists.openstack.org</a>" <<a href="mailto:openstack@lists.openstack.org">openstack@lists.openstack.org</a>><br><span style="font-weight:bold">Subject: </span> [Openstack] How to enable jumbo frames for instances ?<br></div><div><br></div><div xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><meta name="Generator" content="Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--><div lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal">Hi list,<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">I’m working under CentOS 6.4 + Havana + Neutron + OVS + gre.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">I’m testing performance for gre.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">I have a 10Gb/s NIC for compute Node.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">While, the max bandwidth I can get is small then 3Gb/s, even I have enough instances.<o:p></o:p></p><p class="MsoNormal">I noticed the reason the bandwidth can’t reach higher is due to the utilization for one CPU core is already 100%.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">So, I want to try if I can get higher bandwidth if I have bigger MTU, because the default MTU = 1500.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">But, after I set <b><span style="color:red">network_device_mtu=8500</span></b><span style="color:red"></span>in "/etc/nova/nova.conf", and restart openstack-nova-compute service and re-create a new instance, the MTU for devices is still 1500:<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal" style="margin-left:.5in">202: qbr053ac004-d6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu
<b><span style="color:red">1500</span></b><span style="color:red"> </span>qdisc noqueue state UNKNOWN<o:p></o:p></p><p class="MsoNormal" style="margin-left:.5in"> link/ether da:c0:8d:c2:d5:1c brd ff:ff:ff:ff:ff:ff<o:p></o:p></p><p class="MsoNormal" style="margin-left:.5in">203: qvo053ac004-d6: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu
<b><span style="color:red">1500</span></b><span style="color:red"> </span>qdisc pfifo_fast state UP qlen 1000<o:p></o:p></p><p class="MsoNormal" style="margin-left:.5in"> link/ether f6:0b:04:3f:9d:41 brd ff:ff:ff:ff:ff:ff<o:p></o:p></p><p class="MsoNormal" style="margin-left:.5in">204: qvb053ac004-d6: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu
<b><span style="color:red">1500</span></b><span style="color:red"> </span>qdisc pfifo_fast state UP qlen 1000<o:p></o:p></p><p class="MsoNormal" style="margin-left:.5in"> link/ether da:c0:8d:c2:d5:1c brd ff:ff:ff:ff:ff:ff<o:p></o:p></p><p class="MsoNormal" style="margin-left:.5in">205: tap053ac004-d6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu
<b><span style="color:red">1500</span></b><span style="color:red"> </span>qdisc htb state UNKNOWN qlen 500<o:p></o:p></p><p class="MsoNormal" style="margin-left:.5in"> link/ether fe:18:3e:c2:e9:84 brd ff:ff:ff:ff:ff:ff<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Anyone know why is this happen ?<o:p></o:p></p><p class="MsoNormal">How can I solve it ??<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Thanks.<o:p></o:p></p><p class="MsoNormal">-chen<o:p></o:p></p></div></div></div></span></body></html>