> On May 9, 2015, at 2:34 PM, Michael Eager <eager at eagerm.com> 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? 3GB/50seconds = 480Mbps Can't speak directly to centos6/7 differences nor NFS on centos6/7.... I've seen NFS(netapp filer to vmware host to windows VM) sustain 10000Mbps. So the NFS protocol itself isn't the bottleneck given sufficient hardware. Since scp performs similar to NFS the on the wire protocol isn't the problem. Verify the MTU setting: ping a.b.c.d -M do -s 8972 Or in your case: ping a.b.c.d -M do -s 5972 (6000 is a very odd MTU) I'd start by getting the latest/validated driver from $NICVendor. What IO throughput does the local file system give? Test with hdparm / dd / iometer / sqlio / cp -a /path /dev/null Test sever to server with iperf as others suggested. Hope that points you in the right direction. Steven Tardy