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linux_wiki:use_proc_sys_and_sysctl_to_modify_and_set_kernel_runtime_parameters [2016/10/08 17:47] billdozor |
linux_wiki:use_proc_sys_and_sysctl_to_modify_and_set_kernel_runtime_parameters [2019/05/25 23:50] (current) |
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The following virtual machines will be used: | The following virtual machines will be used: | ||
* server1.example.com (192.168.1.150) -> Configure the kernel parameters here | * server1.example.com (192.168.1.150) -> Configure the kernel parameters here | ||
+ | |||
+ | ---- | ||
+ | |||
+ | ====== Help ====== | ||
+ | |||
+ | Finding help in this section. | ||
+ | * Sysctl man page< | ||
---- | ---- | ||
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sysctl -w vm.swappiness=10 | sysctl -w vm.swappiness=10 | ||
sysctl vm.swappiness | sysctl vm.swappiness | ||
+ | |||
+ | # Or | ||
+ | sysctl -a | grep swappiness | ||
</ | </ | ||
* -w -> write | * -w -> write | ||
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* Default system values: / | * Default system values: / | ||
- | * Persistent configuration over rides: / | + | * Persistent configuration over rides: /etc/sysctl.d/filename.conf |
\\ | \\ | ||
- | Create entries in / | + | Create entries in /etc/sysctl.d/ |
<code bash> | <code bash> | ||
vim / | vim / | ||
Line 64: | Line 74: | ||
Load settings from a file | Load settings from a file | ||
<code bash> | <code bash> | ||
- | sysctl -p < | + | sysctl -p / |
</ | </ | ||
* If no file name is specified, defaults to: / | * If no file name is specified, defaults to: / | ||
+ | |||
+ | \\ | ||
+ | Load all settings | ||
+ | <code bash> | ||
+ | sysctl --system | ||
+ | </ | ||
===== Tuned ===== | ===== Tuned ===== | ||
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Tuned is a " | Tuned is a " | ||
- | Starting in EL 7.2, some parameters (such as vm.swappiness) are set AFTER systemd-sysctl.service by the tuned service. | + | * **Notes** |
+ | * Starting in EL 7.2, some parameters (such as vm.swappiness) are set AFTER systemd-sysctl.service by the tuned service. | ||
+ | * In EL 7.4, it appears that tuned defaults to honor sysctl (/ | ||
+ | # Whether to reapply sysctl from the e.g / | ||
+ | # If enabled these sysctls will be re-appliead after Tuned sysctls are | ||
+ | # applied, i.e. Tuned sysctls will not override system sysctls. | ||
+ | reapply_sysctl = 1 | ||
+ | ....SNIP....</ | ||
+ | * Either way; be aware of tuned and its potential to conflict with sysctl. | ||
\\ | \\ |