Le Thu, 5 Sep 2013 19:18:00 +0200 Emmanuel Florac <eflorac@xxxxxxxxxxxxxx> écrivait: > Any hint, idea, etc would be extremely welcome. Even some > debugging method less painful than digging through huge > tcpdumps would be nice :) I post this answer in the faint hope that it may avoid a long and painful week of testing to someone else :) The problem comes from the virtual network adapter "Intel pro 1000" using the e1000e linux driver. The Intel hardware supports a MTU of 4078 max. On a physical machine, it will fail to set up a greater value with something like: # ifconfig eth0 mtu 4079 SIOCSIFMTU: Invalid argument However the virtual e1000 from VMWare ESX silently accept any value; then it will mostly work, and fail in mysterious way and only with certain protocols (such as nfs). In the case of VMWare virtual machines, using a vmnet3 virtual network adapter works fine with a mtu of 9000 under NFS. Therefore the problem is solved. For the sake of completeness and curiosity, I'll try and see what happens with a KVM e1000 virtual device. -- ------------------------------------------------------------------------ Emmanuel Florac | Direction technique | Intellique | <eflorac@xxxxxxxxxxxxxx> | +33 1 78 94 84 02 ------------------------------------------------------------------------ -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html