Linux How to set kernel parameters in sysctl.conf file permanently

How to set kernel parameters in sysctl.conf file permanently in Linux? Specifically RHEL in this case, but this applies to centos as well. Even Suse I believe   The kernel parameters can be tuned dynamically with the sysctl command.  Meaning you can change a kernel parameter on the fly.  But this won’t survive a reboot.  To make this type of change permanently the best and possibly easiest way is to either edit the /etc/sysctl.conf file and then save it with the sysctl -p command below.

Edit /etc/sysctl.conf file

# vi /etc/sysctl.conf

Add or change whatever entries you need to in sysctl.conf, as given below.

kernel.sem=1000 32000 32 512
kernel.msgmni = 1024
fs.file-max = 65535
net.ipv4.tcp_max_syn_backlog = 8192
# set cause we are now a router
net.ipv4.ip_forward = 1
# Controls the maximum size of a message, in bytes
kernel.msgmnb = 32768
# Controls the default maxmimum size of a mesage queue
kernel.msgmax = 65536
# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736
# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296

Confirm that there are no duplicate entries in the /etc/sysctl.conf file. To install the newly configured kernel paramaters, run the sysctl command with the -p parameter. This loads the sysctl settings from the default file /etc/sysctl.conf.

# sysctl -p