How do I update a CentOS server's time from an authoritative time server?

Question

I have CentOS machine and each time I've noticed that the server loses correct time after a while. It is usually behind by several minutes after time passes from having manually set the correct time. Is there a mechanism whereby I can update the server with the time from a specific time server?

score 127 · Accepted Answer · answered Mar 11 '12 at 20:14

127

Use the ntp daemon. Run yum install ntp and ensure that the service is started via ntsysv or chkconfig ntpd on.

To get an immediate sync, run ntpdate time.apple.com (or something similar).

answered Mar 11 '12 at 20:14

ewwhite

201,205

user9517 · Answer 2 · 2012-03-11T20:15:33.850

109

You need to install and configure ntp.

yum install ntp
chkconfig ntpd on
ntpdate pool.ntp.org
service ntpd start

should get things set up and running. You may find that the ntp package is already installed and just needs configuring.

edited Mar 11 '12 at 20:15

answered Mar 11 '12 at 20:13

user9517

117,122

score 14 · Answer 3 · answered Mar 11 '12 at 20:12

14

Yes.

NTP.

yum install ntp
chkconfig ntpd on

Do an initial sync, with

ntpdate pool.ntp.org

and start the time daemon with:

/etc/init.d/ntpd start

answered Mar 11 '12 at 20:12

Tom O'Connor

27,578

uSlackr · Answer 4 · 2012-03-12T01:10:00.850

3

You'll need to configure ntpd for the server. I suspect it is already installed but needs to be configured. Note: if it is a virtual server, you probably have the option of syncing with the virtual host.

edited Mar 12 '12 at 01:10

answered Mar 11 '12 at 20:12

uSlackr

6,452

score 3 · Answer 5 · answered Apr 16 '18 at 18:39

3

For centos 7.x installation:

yum install ntp
systemctl enable ntpd

initial sync, with:

ntpdate pool.ntp.org

start the daemon with:

systemctl start ntpd

answered Apr 16 '18 at 18:39

Ben

131

score 2 · Answer 6 · answered Jul 27 '22 at 21:23

2

In the case of Centos 8, I just start/enble chronyd like below:

systemctl start chronyd
systemctl enable chronyd

answered Jul 27 '22 at 21:23

N_Z

133

score 2 · Answer 7 · answered Mar 11 '12 at 20:10

2

ntpd.

Ntpd does exactly what you're looking for - synchronizes your system clock with one or more known-good time servers.

answered Mar 11 '12 at 20:10

EEAA

110,608

score 2 · Answer 8 · answered Mar 12 '12 at 01:12

Basically there are two ways. NTP daemon and the ntpdate command. The most important difference is that ntpdate will synchronize the time at once even though it means that the system time will change. On the other hand NTP daemon will take care of the time synchronization and it will adjust the time by small steps - you can think about it like slowing down/speeding up the time of the computer to synchronize it to the correct time. Thats why people suggest to do the initial synchronization by ntpdate and then leave it to ntp daemon.

score 1 · Answer 9 · answered Mar 11 '12 at 20:36

1

Yea I'd use NTP, install ntp with yum and turn it on.

yum install ntp
chkconfig ntpd on

Then sync it to any ntp server of your liking with the ntpdate command

answered Mar 11 '12 at 20:36

Lucas Kauffman

16,990

score 0 · Answer 10 · answered May 03 '13 at 12:33

0

Also if using CPanel like I was and had this issue. I think using rdate. Changing to ntpd as per above fixes all issues with email, especially dovecot,etc.

answered May 03 '13 at 12:33

HostKing

1

How do I update a CentOS server's time from an authoritative time server?

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