sysctl : command not found

I found the time to deploy ES failed to start, that I max virtual memory areas vm.max_map_count [65530] is too low, so went modify the /etc/sysctl.conf file, add the vm.max_map_count = 655360
after restart or ES failed, as if no modifications take effect! So I wanted to execute sysctl -p

## 从配置文件“/etc/sysctl.conf”加载内核参数设置；
sysctl -p

But the reality sysctl command can not be found, but whereis sysctl and there, head-big

sysctl: /usr/sbin/sysctl /etc/sysctl.d /etc/sysctl.conf /usr/share/man/man8/sysctl.8.gz /usr/share/man/man2/sysctl.2.gz

I did not have to approach, the user switches to root, and then to perform slightly below sbin

/sbin/sysctl -p

Actually it is not how it was made! After going to look up information, thank you watch!