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How to up date the time of my dedicated server?

Sources of the problem

The problem is usually due to the fact that your server is not on the kernel optimized for its hardware configuration. Therefore, the time of the P4 servers equipped in Hyper Threading is incorrect. In general, you may sort the problem out by booting the server on the correct kernel, the one with the 'optimized for Hyperthreading' mention.

If your server is not in Hyper Threading and you encounter this problem, you just need to follow this manual.

Our manual to up date your kernel via the Netboot is: KernelNetboot.

Manage the time in SSH

Our manual for SSH use: SshOnDedicated.

Log in root on your server via SSH.

To know the time, you just need to type:
[root@delirium angie]# date
Fri Jan 7 15:20:25 CET 2005

To update the date and/or the time, you may use the command:

[root@delirium angie]# date -s

For example, to up date the date of 19/01/2005:

[root@delirium angie]# date -s 01/19/2005

For example to up date the time at 18:08 and 30 seconds:

[root@delirium angie]# date -s 18:08:30

When the time is not up to date, you may automatically synchronise an atomic clock. To do so, we will use ntpdate.

Locate ntpdate:

[root@delirium angie]# whereis ntpdate
ntpdate: /usr/sbin/ntpdate
ntpdate is then installed and is located in /usr/sbin path

Synchronise with ntpdate:

[root@delirium angie]# /usr/sbin/ntpdate
19 Jan 20:27:37 ntpdate[22698]: adjust time server offset 0.152248 sec

ntpdate has updated the time

The synchronisation via ntp may be impossible if the difference is too important. In that case, you may force the up date of the date and/or the time (approximatively) before setting the time via NTP in a more precise way. For the commands, see below.

Automate the update

A list of ntp servers is available here
You may, thanks to a cron task, automate the time update.

Insert the cron task by ssh:
[root@delirium angie]# pico /etc/crontab

Your file will then appear ready for the edition. Add the following information:

#synchronisation ntpdate daily at 3am
0 3 * * * root /usr/sbin/ntpdate >/dev/null

Quit with Ctrl+X and validate with "Y" or "O" then press enter.

You must restart with crond again:

[root@delirium angie]"#" /etc/init.d/crond restart
Stop crond : [OK ]
Crond start: [ OK ]
[root@delirium angie]"#"

Your server will be up dated every day or according to your need.

Find out more about cron tasks here.