Linux is one of the best operating system. Its default settings are almost perfect especially network parameters. I said almost because they are not completely perfect for all situations. Actually, it works perfectly on many situations, e.g., desktop, workstation, and server. For such a normal server, Linux is sufficient for all of us. However, in high performance computing area, the default settings might be not enough at all. So we have to tune network parameters to obtain the top performance.

Simply add below settings to /etc/sysctl.conf and run sysctl -p to activate the change.

net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 87380 16777216 
net.ipv4.tcp_wmem = 4096 65536 16777216
 
net.ipv4.tcp_no_metrics_save = 1
net.core.netdev_max_backlog = 2500
# net.core.netdev_max_backlog = 30000

Tags: linux, high performance computing