Q. How do I set sysctl variables under Debian Linux?
A. sysctl is used to modify kernel parameters at runtime. The parameters available are those listed under /proc/sys/. Procfs is required for sysctl support in Linux. You can use sysctl to both read and write sysctl data.
You must login as the root user to use any one of the following command.
Method # 1: Setting value via procfs
You can use standard echo command to write data to variables:
# echo "value" > /proc/sys/location/variable
Method # 2: Temporary on the command line
Use sysctl command with -w option when you want to change a sysctl setting:
sysctl -w variable=value
Method # 3: Configuration file /etc/sysctl.conf
This is recommended way. First open /etc/sysctl.conf file
# vi /etc/sysctl.conf
Now add value:
variable = value
Close and save the changes. Type the following command to load sysctl settings from the file /etc/sysctl.conf file:
# sysctl -p
Read man page of sysctl for information:
$ man sysctl