Hi Alec, Just ran another test using 1M chunks. The result is: $ time dd if=/dev/zero of=testfile2 bs=1M count=1500 1500+0 records in 1500+0 records out 1572864000 bytes (1.6 GB) copied, 42.8267 s, 36.7 MB/s real 0m42.828s user 0m0.000s sys 0m0.633s I used here a count of 1500 since quota has been enforced on user accounts. By MTU=9000 should apply to the NFS server correct? I'm not sure I understand your experience using jumbo frames. Did it have a positive impact? How was the performance? How about e.g opening browsers, temrinals, editors and other applications. We use zabbix to monitor our systems and from what I can see, there is quite a large I/O wait on the NFS server. Thanks for sharing this with me. On 06/03/2016 06:38 PM, Alec T. Habig wrote: > Patrick J. LoPresti writes: >> How did you wind up with rsize/wsize of 8K? The default on Linux has >> been 1 megabyte for a long time. > Hmm. I've (independently from the original poster) got the 8k sizes: > with the network set up for jumbo frames (MTU=9000) the nfs server then > chunks out network packets that get through the switches with minimal > overhead. Making this change from the default (1k, MTU=1500) made a > huge throughput difference at the time we implemented it: which was a > number of years ago, so certainly the world has changed since then. > > How do 1MB sized nfs chunks interact with the networking? >