# Set system control parameters for specific network device

**URL:** https://forums.suse.com/t/set-system-control-parameters-for-specific-network-device/27327
**Category:** SLES for System Z
**Created:** [August 12, 2015, 12:12pm UTC](https://forums.suse.com/t/set-system-control-parameters-for-specific-network-device/27327 "2015-08-12T12:12:54Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![kobuse](https://avatars.discourse-cdn.com/v4/letter/k/54ee81/32.png) [@kobuse](https://forums.suse.com/u/kobuse)
#### Post date: [August 12, 2015, 12:12pm UTC](https://forums.suse.com/t/set-system-control-parameters-for-specific-network-device/27327/1 "2015-08-12T12:12:54Z")

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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

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### Author: ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)
#### Post date: [August 17, 2015, 7:30am UTC](https://forums.suse.com/t/set-system-control-parameters-for-specific-network-device/27327/2 "2015-08-17T07:30:18Z")

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kobuse,

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