Ok, I stumbled over the kernel parameter /sys/module/nfs/parameters/nfs4_disable_idmapping
which is N on our older (Ubuntu 12.04, Kernel 3.2) clients Y on the newer (Ubuntu 14.04, Kernel 3.13). Setting it to N seems to make chown work again, pulseaudio working too. tcpdump now: 128 1.505072 $SERVER_IP $CLIENT_IP NFS 122 V4 Reply (Call In 127) OPEN Status: NFS4ERR_NOENT Thought that could be helpful, not sure if that is a solution or a workaround
smime.p7s
Description: S/MIME Cryptographic Signature
