Reverting back to the built-in ixgbe module
While doing some performance tuning and such on a 6.7 physical machine with a pair of Intel 10Gb NICs (82599s), someone advised trying the latest 5.x driver from Intel which sounded like a good idea (either it would be worth it or not). Unfortunately this didn't solve what we were looking to solve and folks concerned with the whole kernel upgrade conundrum suggest just putting back the old ixgbe module. Alas, there seems to be no well-documented method (at least from Intel or plenty or searching the web), so does anyone have a clear cut way to drop this "updated" version and make it use the default one?
modinfo ixgbe
filename: /lib/modules/2.6.32-573.el6.x86_64/updates/drivers/net/ethernet/intel/ixgbe/ixgbe.ko
version: 5.0.4
What we need to go back to is:
filename: /lib/modules/2.6.32-573.el6.x86_64/kernel/drivers/net/ixgbe/ixgbe.ko
version: 4.0.1-k
thanks!
Responses
Assuming the driver doesn't come from an RPM, something like this should do it:
service network stop
modprobe -r ixgbe
mv /lib/modules/2.6.32-573.el6.x86_64/updates/drivers/net/ethernet/intel/ixgbe/ixgbe.ko /root/
depmod -a
service network start
Once network is back up, delete the old driver:
rm /root/ixgbe.ko
That's what depmod does, it looks through the drivers available at the time of running and builds a set of dependencies. So when modprobe goes "I have device 8086:10f9 (which is the PCI ID of an 82599_SFP), what driver do I use?" it looks through the files in /lib/modules/ created by depmod and finds a driver which advertises support for that device. As you ran depmod with the third-party driver removed, the in-kernel driver took over all the PCI IDs of ixgbe devices, so the in-kernel ixgbe is loaded by modprobe. I'm not sure why a reboot was required but that's good to know. You can probably safely move/remove the third-party driver file now.
Next time when you wish to try out a newer version, you might want to ask ELRepo ( http://elrepo.org/ ) to build a kmod package for that version. One of the advantages with using a kmod is that it is easy to install AND uninstall. Uninstallation is done by a simple "yum remove kmod-xxx". But more importantly, ELRepo's kmod packages are kABI-tracking, meaning there is no need to rebuild for each kernel update.
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