Sync system time

ust · 05-16-2012, 09:58 PM

I am in Sigapore , the time is GMT +8 , but my linux server time should be set to GMT time (GMT +0) , can advise what is the way that the server can syn with the GMT time accurately ?

I have nine linux servers need to sync with GMT time , the best way is sync with external time server or sync with local server and run script to subtract 8 hours ?

thx

Satyaveer Arya · 05-16-2012, 11:12 PM

Can you show us your /etc/ntp.conf configuration file?

ust · 05-16-2012, 11:22 PM

Quote:

Originally Posted by Satyaveer Arya

Can you show us your /etc/ntp.conf configuration file?

no such file in my redhat server.

Satyaveer Arya · 05-16-2012, 11:26 PM

How could it be? The location of ntp.conf in redhat is under /etc/, anyways try to locate the file.

Code:

# locate ntp.conf

blue_print · 05-16-2012, 11:36 PM

This command will give you the path to ntp configuration file.

Quote:

rpm -ql ntp | grep -i conf

catkin · 05-16-2012, 11:40 PM

You can sync with a time server in any location. It's best to choose ones that are near in network times to minimise differences (jitter) in packet transmission time over the network.

The task is made easy by the NTP pool project which coordinates time servers by regions. The Singapore pool (sg.pool.ntp.org) has five servers. The NTP pool project advises that is not enough so the Asia pool (asia.pool.ntp.org) should be used instead.

If you have an ntpd version that supports the pool directive (4.2.6p1 did, maybe earlier), /etc/ntp.conf can have:

Code:

pool asia.pool.ntp.org

My own ntpd.conf uses the Indian pool followed by the Asian pool. Maybe that's not good practice:

Code:

# Time sources
# ~~~~~~~~~~~~
# Using pool method from /usr/share/doc/ntp-4.2.6p1/html/manyopt.html#pool
# also at http://www.eecis.udel.edu/~mills/ntp/html/manyopt.html#pool

# For India
# (Asia also required because India is inadequate)
pool in.pool.ntp.org
pool asia.pool.ntp.org

Another factor to consider is the quality of network connections. Singapore might have better (= faster, lower latency, less jittery) network connections to say USA than to some of the servers in the asia.pool.ntp.org pool.

Satyaveer Arya · 05-16-2012, 11:48 PM

Quote:

no such file in my redhat server.

I think the ntp package is not installed on your machine, if I'm not wrong?

ust · 05-17-2012, 02:35 AM

Quote:

Originally Posted by Satyaveer Arya

I think the ntp package is not installed on your machine, if I'm not wrong?

I find the file /etc/ntp.conf.dpkg-new in my debian server , is it a configuration file for NTP ?

btmiller · 05-17-2012, 02:57 AM

Sounds like it's a file left by dpkg when it upgraded ntp (rather than overwriting your initial ntp.conf).

This page describes how to change your time zone on an RHEL system. It is also highly recommended to install and run NTP to keep accurate time on your system.

Satyaveer Arya · 05-17-2012, 03:39 AM

Quote:

no such file in my redhat server.

This is from post no. 3

Quote:

I find the file /etc/ntp.conf.dpkg-new in my debian server

and this is from post no. 8

In which OS you're searching the file, RHEL or Debian?