How can I reduce ntp server time?

scbops · 06-27-2008, 03:49 AM

My ntp server is running faster than 30 minutes from actual time. How can correct the time without effecting the any application in ntp server and ntp clients

Note: - I have reduce the time once (some time back) using date command it was effected to My ntp server application (db2 database) and it got stuck.

I would like to reduce time once in 5 minutes by 1 minute. Is there a ntp command to do this?

My OS is RHEL 4.3

acid_kewpie · 06-27-2008, 04:14 AM

You can't easily do that with single commands, you could write a shell script to step it slowly, but the only real option would be the -B option on the ntpdate commmand, which will slew a BIG time difference rather than step it. 30 minutes is a BIG BIG time though, and looking at the ntpd manpage the maximum slew rate is 0.5ms/s, which for a 30 minute correction would equate to about 1000 hours (41 days) to correct the time if that still applies here.

http://www.eecis.udel.edu/~ntp/ntp_s...l/ntpdate.html
http://www.eecis.udel.edu/~ntp/ntp_spool/html/ntpd.html

andymalato · 06-27-2008, 08:12 AM

I would schedule some downtime for this system, shutdown db2, correct the time, then bring it back online.

HTH.

scbops · 06-30-2008, 12:23 AM

I have corrected the time in several times in the pass (once in an every 7-8 months).
I appreciate if someone can provide the direct ntp command for this.

acid_kewpie · 07-02-2008, 03:51 AM

as above, just a standard ntpdate with the -B option. Once the time is correct then you should run the ntpd service to constantly keep it accurate.