On 1/7/20 5:32 AM, RENARD Pierre-Francois wrote: > > Hello all > > I am facing an issue related to Raspberry PI 3B+ and onboard ethernet card. > > When doing a huge transfer (more than 1GB) in a row, transfer hanges and failed after a few minutes. > > > I have two ways to reproduce this issue > > > using NFS (v3 or v4) > > dd if=/dev/zero of=/NFSPATH/file bs=4M count=1000 status=progress > > > we can see that at some point dd hangs and becomes non interrutible (no way to ctrl-c it or kill it) > > after afew minutes, dd dies and a bunch of NFS server not responding / NFS server is OK are seens into the journal > > > Using SCP > > dd if=/dev/zero of=/tmp/file bs=4M count=1000 > > scp /tmp/file user@server:/directory > > > scp hangs after 1GB and after a few minutes scp is failing with message "client_loop: send disconnect: Broken pipe lostconnection" > > > > > It appears, this is a known bug relatted to TCP Segmentation Offload & Selective Acknowledge. > > disabling this TSO (ethtool -K eth0 tso off & ethtool -K eth0 gso off) solves the issue. > > A patch has been created to disable the feature by default by the raspberry team and is by default applied wihtin raspbian. > > comment from the patch : > > /* TSO seems to be having some issue with Selective Acknowledge (SACK) that > * results in lost data never being retransmitted. > * Disable it by default now, but adds a module parameter to enable it for > * debug purposes (the full cause is not currently understood). > */ > > > For reference you can find > > a link to the issue I created yesterday : https://github.com/raspberrypi/linux/issues/3395 > > links to raspberry dev team : https://github.com/raspberrypi/linux/issues/2482 & https://github.com/raspberrypi/linux/issues/2449 > > > > If you need me to test things, or give you more informations, I ll be pleased to help. > I doubt TSO and SACK have a serious generic bug like that. Most likely the TSO implementation on the driver/NIC has a bug . Anyway you do not provide a kernel version, I am not sure what you expect from us.
