sysctl settings not persistent after reboot. Setting in ‘/etc/sysctl.d/*.conf’ are not applied.
The syntax of ‘sysctl.conf‘ is as shown below:
token = value
Note that blank lines are ignored, and whitespace before and after a token or value is ignored, although a value can contain whitespace within.
The parameters need to be set without any punctuation or quotations. For example
For CentOS/RHEL 7
1. For CentOS/RHEL 7 systems first check if ‘sysctl.service‘ was successfully loaded:
$ systemctl list-units | grep sysctl
2. Also check the journal logs for any issues related to the sysctl.service:
$ journalctl -u systemd-sysctl.service
3. Check all the sysctl files and their value format in the below configuration files:
/etc/sysctl.conf /etc/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf
How to query and modify kernel parameters using sysctl (Immediately and persistently) in CentOS / RHEL
How sysctl parameters are executed in CentOS/RHEL 7