Kernel module parameters are not changing even after a reboot?

shanebagel · 06-16-2022, 11:49 AM

I have a device driver which is a kernel module: virtio_net
It has the parameters csum which is a boolean

I set it to OFF with modprobe virtio_net csum=0
I set it to OFF persistently by creating a file in /etc/modprobe.d with the content: options virtio_net csum=0

I reboot server

I run systool -vm virtio_net

The parameter is set to OFF is still showing ON?
What gives?

ondoho · 06-16-2022, 11:53 AM

Quote:

Originally Posted by shanebagel

I have a device driver which is a kernel module: virtio_net
It has the parameters csum which is a boolean

I set it to OFF with modprobe virtio_net csum=0
I set it to OFF persistently by creating a file in /etc/modprobe.d with the content: options virtio_net csum=0

I reboot server

I run systool -vm virtio_net

The parameter is set to OFF is still showing ON?
What gives?

Who knows. Any other process with root privileges could change it back.
Would it be an option to simply blacklist the module?

shanebagel · 06-16-2022, 12:39 PM

I could definitely do that, just curious to see how modprobe can be used to change the module parameters.