Turning off GRO on startup

[bomahony]

So i have a system that is on two different networks. Each NIC is on its own subset etc.

I was seeing a huge amount of issues with one of them, and it turned out it had:
generic-receive-offload: on

Once i turned this off with "ethtool -K eth1 gro off", everything is working fine. HOWEVER when i reboot, it gets re-enabled.

Is there a way to turn this off on startup?

[I do realise i can turn it off by adding to rc.local, i am just wondering if there is a "cleaner" method]

[atreyu]

Have you tried putting them in the appropriate ifcfg config file? e.g.

# /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE="eth0"
ONBOOT="yes"
ETHTOOL_OPTS="gro off"

That is untested, but I think that is where it would go.

[bomahony]

Doesnt seem to be working. However I cant reboot this system until 30th December, so im testing on another machine by trying to turn GRO on at boot using "gro on".

[atreyu]

Does that device on the other machine take the "gro on" command from the command line okay? Probably so, just checking...

[atreyu]

Okay, seems using ethtool with -K type options in network-scripts is a bug.

There is a patch listed on the bug report that would allow you to do something like:

ETHTOOL_OPTS_OFFLOAD="gro off"

But you'd have to keep track of that file and make sure that updates to the package that own the patched file(s) don't get overwritten.

Or you could make it a udev rule like is suggested in the bug report...

[bomahony]

Yeah - checked that before i rebooted

[bomahony]

Giving it a look now. To be honest, I will probably go with the entry to rc.local. I dont get to patch these machines. Ever. They have to be used with specific RHEL version, specific drivers, kernels etc.

Thanks for all your help mate!

[atreyu]

Yeah, I understand that. Just keep in mind that putting it in rc.local might only affect it upon start-up, i.e., do you know if that change is persistent across network restarts?

e.g., if you do:

service network restart

Is gro stilll off?

[bomahony]

Like i said, I am working with gro "on" in a VM for testing purposes (same version of RHEL etc).

Added to rc.local, it started with it on. When i ran "service network restart" it stayed on. I would rather get the patch in place, but this will do until my next downtime at a pinch.

And realistically, i dont get to run service network restart. Ever. I never get to do anything on the systems outside downtime (they are in use 24/7 and i get maybe 4 downtimes a year)

[atreyu]

Sorry, "on"...I lost track of which way you wanted it.

The only reason I mentioned network restarts is in case they ever get restarted w/o your say-so, but if you've tested it, then sounds like you're golden.