On RHEL, OEL, CentOS and various other Linux distribution the Network Time Protocol (NTP) daemon can be run with various options. As the daemon is usually defined as a service where managed by:
- /etc/init.d/ntpd <…>
- service ntpd <…>
commands, it is better to use the configuration file
/etc/sysconfig/ntpd
to set the arguments. The file looks like:
# Drop root to id ‘ntp:ntp’ by default.
OPTIONS=”-x -u ntp:ntp -p /var/run/ntpd.pid”# Set to ‘yes’ to sync hw clock after successful ntpdate
SYNC_HWCLOCK=no# Additional options for ntpdate
NTPDATE_OPTIONS=””
Above you can see that the command line arguments are setup by the OPTIONS configuration variable.
You can check the settings from that /etc/sysconfig/ntpd file but it will not be reliable if the ntpd process is started manually for some reason. To check the arguments you can use command line:
ps -o args -p `cat /var/run/ntpd.pid`
and the output will look like:
# ps -o args -p `cat /var/run/ntpd.pid`
COMMAND
ntpd -x -u ntp:ntp -p /var/run/ntpd.pid
#
