I am using a network interface (zVM Vswitch - IBM OSA card) - eth0 and HiperSockets - hsi0. The two networks works 100% but I would like to do some tuning. I know that you can set system wide parameters in /etc/sysctl.conf. My question is : How do you override the system wide setting (it is set up as optimal for the virtual switch interface eth0). I want to set specific parameters (for example - net.core.wmem_max = 524288 and net.core.rmem_max = 524288) to optimize the HiperSocket (hsi0) interface. The current settings in sysctl.conf is net.core.wmem_max = 4194304 and net.core.rmem_max = 4194304. (Optimal for the the eth0 device)

Any help would be appreciated