User`s guide

4: Performance Tuning
sizes were chosen to be compatible with those recommended by the card
manufacturer and required by SGI’s software. To set the network buffer sizes:
1. Add or change the following entries in the /etc/sysctl.conf file:
net.core.rmem_default = 524287
net.core.rmem_max = 524287
net.core.wmem_default = 524287
net.core.wmem_max = 524287
net.ipv4.tcp_rmem = 10000000 10000000 16777216
net.ipv4.tcp_wmem = 10000000 10000000 16777216
net.ipv4.tcp_mem = 10000000 10000000 16777216
net.core.netdev_max_backlog = 300000
net.core.optmem_max = 524287
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
2. Make the sizes take effect:
[root@linux root]# sysctl -p /etc/sysctl.conf
TCP Time Stamps
TCP time stamps are turned on by default to greatly reduce the chance of data
corruption at high throughput rates. Therefore, SGI strongly recommends their use.
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