Linux oracle синхронизация времени

When an Oracle VM Server is discovered from Oracle VM Manager, NTP (Network Time Protocol) is automatically configured and enabled to ensure time synchronization. Oracle VM automatically configures Oracle VM Manager as the NTP source for all Oracle VM Servers under its control.

However, to provide time services to the Oracle VM Servers, NTP must first be installed and configured on the Oracle VM Manager host server. Make sure that your Oracle VM Manager host is either registered with the Unbreakable Linux Network (ULN) or configured to use Oracle’s public YUM service.

To configure NTP on the Oracle VM Manager host:

# vi /etc/ntp.conf server 0.rhel.pool.ntp.org server 1.rhel.pool.ntp.org server 2.rhel.pool.ntp.org

#restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap

# service ntpd start # chkconfig ntpd on

# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== lists2.luv.asn. 203.161.12.165 16 u 25 64 3 3.495 -3043.1 0.678 ns2.novatelbg.n 130.95.179.80 16 u 27 64 3 26.633 -3016.1 0.797 sp1.mycdn.fr 130.234.255.83 16 u 24 64 3 4.314 -3036.3 1.039

# ntpq -c rv assID=0 status=c011 sync_alarm, sync_unspec, 1 event, event_restart, version="ntpd 4.2.4p8@1.1612-o Tue Jul 6 21:50:26 UTC 2010 (1)", processor="x86_64", system="Linux/2.6.32-200.19.1.el6uek.x86_64", leap=11, stratum=16 , precision=-20, rootdelay=0.000, rootdispersion=1.020, peer=0, refid=INIT, reftime=00000000.00000000 Thu, Feb 7 2036 17:28:16.000, poll=6, clock=d21d4a96.a26c5962 Fri, Sep 16 2011 14:09:58.634, state=0, offset=0.000, frequency=0.000, jitter=0.001, noise=0.001, stability=0.000, tai=0

If the server is showing stratum=16 , wait a few minutes and try again. It may take up to 15 minutes for an NTP server to stabilize sufficiently to lower its stratum level. Downstream clients will not synchronize with a server at stratum level 16. Once the stratum level has dropped, log in to any available Linux host in your management network and issue the following command:

# ntpdate -d manager.hostname [. ] 16 Sep 13:58:25 ntpdate[1603]: step time server 192.168.1.1 offset 3.009257 sec

Once you have confirmed with these tests that NTP is working properly for your environment, you should not need to check this again.

NTP communicates over UDP port 123. Ensure that no firewall is blocking this traffic.

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Configure Chrony on Oracle Linux

The following tutorial provides step-by-step procedures to configure date and time, and enable Chrony. This tutorial is targeted at Oracle Linux 8 users, but the commands are also available on other Oracle Linux releases.

Objectives

What Do You Need?

Note: When using the free lab environment, see Oracle Linux Lab Basics for connection and other usage instructions.

Configure System Date and Time

In this practice, you use the date , hwclock , and timedatectl utilities to configure and display date and time information.

Open a terminal and connect to your Oracle Linux instance.
Become the root user.

The current date and time displays.
Run the date command with the argument to view the weekday name.

Run the date command with the argument to view the month name.

Use the date command to change the date to another date, for example 14 December, 2021. You can substitute any date.

Use the date command to change the date to the correct date, for example 03 February, 2021.

Use the date command to change the time to your current local time. For example, 08:57 AM.

Run the hwclock command with no arguments to display the hardware clock’s current date and time.

Use the hwclock command with the –w option to set the hardware clock to the current system time.

The variation in seconds is due to the delay between running the two commands.
Run the timedatectl command with no arguments to display the system date and time information.

If the above output shows NTP service: active, disable it as follows and re-check it:

timedatectl set-ntp 0 timedatectl

Use the timedatectl command to change the date to the correct date.

Substitute today’s correct date. The example changes the date to 27 January, 2021.
Run the timedatectl command afterwards with no arguments to verify that the date changed.

timedatectl set-time 2021-01-27 timedatectl

Substitute the current local time. The example changes the time to 09:11:30 AM.
Enter the hour using a 24-hour clock.
Run the timedatectl command afterwards with no arguments to verify that the time changed.

timedatectl set-time 09:11:30 timedatectl

Configure NTP Using Chrony

In this section, you configure NTP using chrony .

root

Use the systemctl command to start chronyd if necessary.

Alternatively, you could run chronyc to display a chronyc> prompt, and then run the tracking command from the chronyc> prompt.
Type quit to exit the chroncyc prompt.
Sample output is shown.

Reference ID: Refers to the server providing synchronization.
Stratum: The distance from a computer attached to a highly accurate reference clock.
Ref time: The most recent time Chrony utilized a time measurement from the server providing synchronization (time is UTC).

More Learning Resources

Explore other labs on docs.oracle.com/learn or access more free learning content on the Oracle Learning YouTube channel. Additionally, visit education.oracle.com/learning-explorer to become an Oracle Learning Explorer.

For product documentation, visit Oracle Help Center.

More Learning Resources

For product documentation, visit Oracle Help Center.

Configure Chrony on Oracle Linux

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