On 09-05-2015 15:34, Michael Eager wrote: > I am setting up a file server with CentOS 7. I'm seeing > performance which is considerably slower than a similar > server running CentOS 6.6. A 3Gb directory can be copied > to/from the CentOS 6.6 server in about 50 seconds. The > same directory takes about 270 seconds to copy to/from > the CentOS 7 system. > > I see the same performance difference with NFS mounted > file systems or using scp, so it doesn't appear to be > an NFS issue. The MTU on the NICs on both systems is > 1500, and changing it to 6000 on the CentOS 7 system had > no effect. > > Anyone have any ideas what might cause this problem or > how to fix it? > You may test only your network performance, using iperf, iperf3 or netperf, and then test your disk IO (others may indicate tools for this). Currently you are measuring two big subsystems which can have its down issues and/or affect each other. By splitting the test you may get a better picture of what is better/worse. If you can sustain near line rate on iperf, the issue is probably somewhere else then. Marcelo