On Wed, Oct 28, 2009 at 07:46:55AM -0700, Rik van Riel wrote: > I have been tracking down what I thought was a KVM related network > issue for a while, however it appears it could be a hardware issue. > > The symptom is that data in network packets gets corrupted, before > the checksum is calculated. This means the remote host can get > corrupted data, with no way to calculate it (except application > level checksums). Luckily ssh has such checksums, so my rsync over > ssh backup script discovered this issue. > > On a very regular basis, I got this message from ssh: > > Corrupted MAC on input. > > I have played around a bit and narrowed it down to the following: > > ipv4 => no problem > ipv6 w/o tso => no problem > ipv6 with tso => occasional data corruption > > Disabling tso with ethtool -K eth0 tso off makes the problem stop. > > I am running Fedora 12's 2.6.31.1-56.fc12.x86_64 kernel, with the > following hardware: > > 05:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5761 > Gigabit Ethernet PCIe (rev 10) > > I do not know enough about the network layer to know whether this is > fixable in software or whether TSO offloading for ipv6 should just > be disabled on this model. This problem sounds familiar. There are chip bugs in this area, but as far as I know, they should have been worked around. Let me see if this is indeed the same bug resurfacing. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
