Guys,

I am looking to point our linux redhat ES4 to the NTP (time synchronization). Where do I start?


Btw, we have updated the DST (installed tzdata-2006-1.EL4.noarch.rpm and then copied /usr/share/zoneinfo/PST8PDT to /etc/localtime)to four of our linux servers last year, but only 2 works. The other 2 don’t work at all (the same steps were taken).

The servers were never rebooted at all for all four.

When I ran zdump -v /etc/localtime |grep 2008, I get the following (it does show the correct time frame):

[root@lnx2 etc]# zdump -v /etc/localtime |grep 2008
/etc/localtime Sun Mar 9 09:59:59 2008 UTC = Sun Mar 9 01:59:59 2008 PST isdst=0 gmtoff=-28800
/etc/localtime Sun Mar 9 10:00:00 2008 UTC = Sun Mar 9 03:00:00 2008 PDT isdst=1 gmtoff=-25200
/etc/localtime Sun Nov 2 08:59:59 2008 UTC = Sun Nov 2 01:59:59 2008 PDT isdst=1 gmtoff=-25200
/etc/localtime Sun Nov 2 09:00:00 2008 UTC = Sun Nov 2 01:00:00 2008 PST isdst=0 gmtoff=-28800

I do notice the two servers that work have an extra file (locales.conf), but they again, the server at home do not have the extra file. Not sure if it make any differences.

[root@lnx3 etc]# ls -l local*
-rw-r--r-- 1 root root 362 May 12 2007 locales.conf
-rw-r--r-- 1 root root 837 Sep 11 2007 localtime
-rw-r--r-- 1 root root 844 Sep 11 2007 localtime.bak

TIA,
tnt

A few things...

As you've seen, /etc/localtime is what determines how the time-zone is handled. I usually use a symbolic link (the ln -s command) to establish this file as a "link to" the appropriate file in /usr/share/zoneinfo, but that's just me.

Most frequently, a "daemon" process called ntpd is used to automatically synchronize the clock with a time-server. There's also a console-command ntpdate that the root-user can use.

Either way, it's probably going to take some disto-specific setup on your part...