Description of problem:


When you configure an Infinibnad network in rhev-manager it defaults to datagram mode. This mode only allows for MTU size of 2044. We need to allow for the rhev-manager to configure an IPoIB network with either datagram mode or connected mode. If connected mode is configured, then the user supplied non-default MTU size should be used. If datagram mode is used, the default MTU 2044 should be used.

I wrote a short hook to make this work, but it needs to be integrated into the rhev-manager networking configuration tabs, and supported in vdsm.


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Using VDSM hooks. T

copy this file into /usr/libexec/vdsm/hooks/after_network_setup

chmod +x on it


cat /usr/libexec/vdsm/hooks/after_network_setup/01-ib-connected-mode.sh

-----------------------


#!/bin/bash

# VDSM hook to force Infiniband mode from default datagram to connected mode
# Configure MTU in Network tab of OVIRT/RHEVM with Custom MTU - should be 66520 for connected mode

echo "TYPE=Infiniband" >> /etc/sysconfig/network-scripts/ifcfg-ib0
echo "CONNECTED_MODE=yes" >> /etc/sysconfig/network-scripts/ifcfg-ib0
/usr/sbin/ifdown ib0
/usr/sbin/ifup ib0

if grep -Fxq connected /sys/class/net/ib0/mode
then
return 0
else
return 1
fi


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