3.5.1 Matrix Server Administration Guide

Chapter 8: Configure MxFS-Linux 170
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interface. (Check the documentation for your NIC to determine
whether changing the value is supported.) The adjustment may allow
the network stack to continue queuing data to the interface after the
internal hardware buffers are completely used. Be conservative when
increasing the value. The recommended value is 5000.
NFS Clients
See “NFS Clients” on page 164 for information about mount options that
can affect client operations.
Perform Tuning Operations
Tuning Parameters
To improve performance, we recommend that you change the following
parameters. The changes produce a better starting point for NFS
operations on Enterprise-class systems than using the default Operating
System values.
NOTE: These changes are appropriate for the Linux kernels supported
with this release of Matrix Server. Other kernels and other types of
workloads may require different changes.
The following table describes the parameters to be changed. “Adjust the
Tuning Parameters” on page 172 describes how to set the parameters.
Tuning Point OS Default Recommended
net.ipv4.tcp_rmem
TCP read autotuning buffer limits:
low = minimal guaranteed size
pressure = override net.core.rmem_default
max = maximum size of TCP receive buffer does
not override net.core.rmem_max
“4096 87380
174760”
“4096 524288
16777216”
net.ipv4.tcp_wmem
TCP write autotuning buffer limits (same as
net.ipv4.tcp_rmem).
“4096 16384
131072”
“4096 524288
16777216”
net.ipv4.tcp_timestamps
Enable/disable TCP timestamps. Disabling the
timestamps reduces the CPU cost during heavy
traffic situations.
10