Hi everyone, I'm running a simple test with ganesha-next (but the issue exists at least in latest V2.5.5-stable): $ sudo mount -t nfs -o v4.0,users,nolock,soft,timeo=2,retrans=3 127.0.0.1:/ /mnt/nfs $ dd if=/dev/zero of=/mnt/nfs/dump/pw.1 bs=1024k count=2048 conv=fdatasync dd: error writing '/mnt/nfs/dump/pw.1': Input/output error 1616+0 records in 1615+0 records out 1693450240 bytes (1,7 GB, 1,6 GiB) copied, 8,28076 s, 205 MB/s $ sudo mount -t nfs -o users,nolock,soft,timeo=2,retrans=3 127.0.0.1:/ /mnt/nfs $ dd if=/dev/zero of=/mnt/nfs/dump/pw.1 bs=1024k count=2048 conv=fdatasync 2048+0 records in 2048+0 records out 2147483648 bytes (2,1 GB, 2,0 GiB) copied, 6,27708 s, 342 MB/s The second mount is using nfs v4.1. I don't have anything special in my configuration. If I do the dd with a blocksize of 512k, it works fine. If I set rsize/wsize to 524288 as mount options, the dd with bs=1024k still fails. The only log line I get is the following: 25/09/2018 13:47:25 : epoch 5baa2036 : caipirinha : ganesha.nfsd-2381[svc_182] rpc :TIRPC :EVENT :svc_ioq_flushv() writev failed (104) Thanks for your help. Best Regards -- Boris Faure Software Engineer -- <https://www.scality.com/download-idc-marketscape/?utm_source=ScalityEmail&utm_medium=Email&utm_campaign=2018Predictions>