hw csum failure

[Dave Johnston]

With Fuel 6.0 and GRE we experienced a high volume of 'hw csum failure' errors on Cisco UCS hardware.
The csum error was usually followed by a backtrace in the kern.log, which grew to GB, and every few days we experienced crashes on the hypervisor.

The bug appears to be caused by an issue with the kernel module failing to calculate the cksum correctly after the packet is encapsulated.

This has been fixed and backported into Ubuntu precise - but it looks like this hasn't been included in the distribution with Fuel 6.0.

See https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1409123 for details of the bug.

We spent alot of time attempting to upgrade firmware to diagnose this. It would be good to get it included in the distribution or documented somewhere.

[Michael Semenov (msemenov)]

Evgeniya, can you please clarify about Cisco UCS hardware availability for reproducing and testing this issue?

[Stanislav Makar (smakar)]

This bug was incomplete for more than 4 weeks. We cannot investigate it further so we are setting the status to Invalid. If you think it is not correct, please feel free to provide requested information and reopen the bug, and we will look into it further.