[ovs-discuss] a question about userspace ovs

[Chandran, Sugesh]

Regards
_Sugesh

From: qintao (F) [mailto:qintao5 at huawei.com]
Sent: Friday, July 22, 2016 8:09 AM
To: Chandran, Sugesh <sugesh.chandran at intel.com>
Cc: wuhao 00271188 <w00271188 at notesmail.huawei.com.cn>; guoyilong 00231009 <g00231009 at notesmail.huawei.com.cn>; lukai 00197897 <l00197897 at notesmail.huawei.com.cn>; liuguifeng 00230956 <l00230956 at notesmail.huawei.com.cn>; qintao (F) <qintao5 at huawei.com>; wangmeiling 00346626 <w00346626 at notesmail.huawei.com.cn>; kangxu 00360128 <k00360128 at notesmail.huawei.com.cn>
Subject: a question about userspace ovs


Dear sugesh,

Recently I have met a problem when I do some tests. The first following picture  is my network structure. As the second and third following picture show ,
the problem is that the vm(192.168.0.16) cannot ping another vm(192.168.0.19) successfully when being adopted the big size packets ,such as the mtu 1500 .
But after being adopted the small size packets ,such as the mtu 64 ,the vm(192.168.0.16) can ping another vm (192.168.0.19)successfully. And then I chose the
netperf as my  test tool .Whatever the size of the packets I have changed , the packets generated by the netperf have been dropped fully by the port dpdk ,when I run
the command "watch -d -n 1 ovs-ofctl dump-ports br0".And the I found the numbers of free  hugepages on  my host is zero. So I have a doubt it if the problem  has
something to do with it ,or other reasons?
[Sugesh] Looks to me that the MTU on your interfaces are not sufficient to handle the 1500 traffic because every vxlan traffic adds up 50 bytes of additional overhead.


Best regards,

Tony QIN

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