Quantum 6-01376-07 manual NFS / Cifs

It is usually best to configure the RAID stripe size no greater than 256K

for optimal small file buffer cache performance.

For more buffer cache configuration settings, see Mount Command

Options on page 17.

It is best to isolate NFS and/or CIFS traffic off of the metadata network to

NFS / CIFS

eliminate contention that will impact performance. For optimal

performance it is necessary to use 1000BaseT instead of 100BaseT. On

NFS clients, use the vers=3, rsize=262144 and wsize=262144 mount

options, and use TCP mounts instead of UDP. When possible, it is also

best to utilize TCP Offload capabilities as well as jumbo frames.

It is best practice to have clients directly attached to the same network

switch as the NFS or CIFS server. Any routing required for NFS or CIFS

traffic incurs additional latency that impacts performance.

It is critical to make sure the speed/duplex settings are correct, because

this severely impacts performance. Most of the time auto-detectis the

correct setting. Some managed switches allow setting speed/duplex (for

example 1000Mb/full,) which disables auto-detectand requires the host to

be set exactly the same. However, if the settings do not match between

switch and host, it severely impacts performance. For example, if the

switch is set to auto-detect but the host is set to 1000Mb/full, you will

observe a high error rate along with extremely poor performance. On

Linux, the mii-diagtool can be very useful to investigate and adjust speed/

duplex settings.

If performance requirements cannot be achieved with NFS or CIFS,

consider using a StorNext Distributed LAN client or fibre-channel

attached client.

It can be useful to use a tool such as netperf to help verify network

performance characteristics.

StorNext File System Tuning Guide

6