Linux kernel parameter can be changed on the fly using sysctl command. Sysctl helps to configure the Linux kernel parameters during runtime.
# sysctl –a dev.cdrom.autoclose = 1 fs.quota.writes = 0 kernel.ctrl-alt-del = 0 kernel.domainname = (none) kernel.exec-shield = 1 net.core.somaxconn = 128 net.ipv4.tcp_window_scaling = 1 net.ipv4.tcp_wmem = 4096 16384 131072 net.ipv6.route.mtu_expires = 600 sunrpc.udp_slot_table_entries = 16 vm.block_dump = 0
Modify Kernel parameter in /etc/sysctl.conf for permanent change
After modifying the kernel parameter in the /etc/sysctl.conf, execute sysctl –p to commit the changes. The changes will still be there after the reboot.
# vi /etc/sysctl.conf # sysctl –p
Modify kernel parameter temporarily
To temporarily modify a kernel parameter, execute the following command. Please note that after reboot these changes will be lost.
# sysctl –w {variable-name=value}