Originally posted by: RajputAjay

Hi,
I am synchronizing UNIX system with ntp server through xntpd process.
The system gets synchronized whenever i start xntpd process. But when i change the system time by 5 to 10 minutes, it takes a lot of time to get synchronized.

Also, i tried by ntpdate command. It was successfully synchronized with it. But i am not able to set the ntpdate command in CRONTAB sheduler by following command.

1 * * * * /usr/sbin/ntpdate –u 192.168.20.150
The system shows message "command not found".
Can you help me for both the problems.

Originally posted by: shargus

"when i change the system time by 5 to 10 minutes, it takes a lot of time to get synchronized."

That is how NTP is designed. It "slews" the clock slowly to avoid any sudden jumps in time that would confuse things like logs, databases, incremental backups, etc.

Also, if the difference between the clock and the NTP time is very big (1000 seconds, by default), NTP will refuse to start up, since that indicates something is very wrong with the clock.

Take a look at the slewalways and ignore_bigtimestep options in ntp.conf.

xntpd is really intended to maintain the clock by making minor adjustments to keep it in sync (which is usually what you want). Use ntpdate -b once at boot time to step the clock and do the initial sync, then start up xntpd (usually done through rc.tcpip) to keep the clock in sync.