Tuesday, April 10, 2012

Fixing Date, Time and Zone on RHEL 6 command line

Had to fix all time related issues on a remote RHEL 6 server which runs without any windowing system. Plain ol' command line. Documenting steps here for future reference:

Check to see if your date and timezone settings are accurate:
# date
# cat /etc/sysconfig/clock

The server I accessed had wrong settings for both the commands. Here are the steps I used to correct:

Find out your timezone from the folder /usr/share/zoneinfo
# ls /usr/share/zoneinfo

Mine was pointing to America/EDT instead of Asia/Calcutta

Update and save the /etc/sysconfig/clock file to
# sudo vi /etc/sysconfig/clock
ZONE="Asia/Calcutta"
UTC=true
ARC=false

Remove the /etc/localtime
# sudo rm /etc/localtime

Create a new soft link to your time zone
# cd /etc
# sudo ln -s /usr/share/zoneinfo/Asia/Calcutta /etc/localtime
# ls -al localtime
Now it should show the link to your time zone

Set your hardware clock to UTC
# sudo hwclock --systohc --utc
# hwclock --show

Update your time from a NTP server (Red Hat NTP server used here)
# sudo ntpdate clock.redhat.com
10 Apr 22:08:27 ntpdate[25695]: adjust time server 66.187.233.4 offset 0.004185 sec

Finally verify the date now
#date --utc
Tue Apr 10 16:39:56 UTC 2012

#date
Tue Apr 10 22:09:58 IST 2012

Add the above ntpdate command in your server startup script or in a cron job to automatically set the system time. The list of ntp servers can be found here: https://support.ntp.org/bin/view/Servers/StratumOneTimeServers

16 comments:

  1. Thank you , very helpful

    ReplyDelete
  2. It Me Aman,
    Thank you Very much. its make success my 3 days hard work.

    ReplyDelete
  3. I think the command should be
    #sudo ln -s /usr/share/zoneinfo/Asia/Calcutta /etc/localtime

    ReplyDelete
    Replies
    1. Yes you are right .. not sure how that got missed :) .. fixed the omission and thanks!

      Delete
  4. Hey Chetan,

    you saved my day. Thank you very much.

    Daniel

    ReplyDelete
  5. great it works, fine. thanks

    ReplyDelete
  6. Nice guide thanks!

    ReplyDelete
  7. thank you very much Chetan

    work great!!

    lideth :D

    ReplyDelete
  8. Thank you. This really saved my time.

    ReplyDelete
  9. THANKS SAVED ME HEAPS

    ReplyDelete