LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices


Reply
  Search this Thread
Old 09-13-2009, 03:50 PM   #1
GregLee
Member
 
Registered: Feb 2004
Location: Waimanalo, HI
Distribution: Slackware 10, Fedora 6
Posts: 308

Rep: Reputation: 30
Question ntp time 12 minutes slow


My Linux system shows a current time with the date command that is 12-14 minutes behind the time shown by my DirecTV satellite receiver or my wife's MS Vista system. ntpd is running; it's polling several ntp servers; ntpstat claims that the system time is accurate to 11ms. What could be going wrong?
 
Old 09-13-2009, 04:07 PM   #2
michaelk
Moderator
 
Registered: Aug 2002
Posts: 21,501

Rep: Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110
Post the output of the command
ntpq -p
 
Old 09-13-2009, 05:36 PM   #3
GregLee
Member
 
Registered: Feb 2004
Location: Waimanalo, HI
Distribution: Slackware 10, Fedora 6
Posts: 308

Original Poster
Rep: Reputation: 30
Code:
# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 redline.mednor. 209.81.9.7       2 u  350 1024  337   82.043  795371. 2333.87
 ns1.anodized.co 173.14.47.149    2 u  113 1024  377  137.579  793749. 1916.71
 198.186.191.229 199.165.76.11    2 u   21 1024  377   75.466  795758. 1815.77
*LOCAL(0)        .LOCL.          10 l   31   64  377    0.000    0.000   0.001
 net.its.hawaii. .STEP.          16 u  14d 1024    0    0.000    0.000   0.000
 
Old 09-13-2009, 05:49 PM   #4
michaelk
Moderator
 
Registered: Aug 2002
Posts: 21,501

Rep: Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110
Basically none of the time servers are good enough to use (look at the values for offset and jitter) so ntp has defaulted to your local clock. Note the * beside LOCAL(0).

What does your /etc/ntp.conf file contain for servers?
server 0.us.pool.ntp.org
server 1.us.pool.ntp.org
server 2.us.pool.ntp.org


Offset is the difference between your clock and the server.

Jitter is a measurement of stability of the timer server.

Changing the clock within a couple of minutes will help sync your system to a ntp server faster.

Last edited by michaelk; 09-13-2009 at 06:18 PM. Reason: Additional information
 
Old 09-13-2009, 06:23 PM   #5
GregLee
Member
 
Registered: Feb 2004
Location: Waimanalo, HI
Distribution: Slackware 10, Fedora 6
Posts: 308

Original Poster
Rep: Reputation: 30
Quote:
Originally Posted by michaelk View Post
Basically none of the time servers are good enough to use (look at the values for offset and jitter) so ntp has defaulted to your local clock. Note the * beside LOCAL(0).

What does your /etc/ntp.conf file contain for servers?
Oh, so that's what "*" means. But I don't know what is the problem with the last server listed. Here are the servers requested in ntp.conf:
Code:
server 0.fedora.pool.ntp.org
server 1.fedora.pool.ntp.org
server 2.fedora.pool.ntp.org
server 127.127.1.0
server ntp.hawaii.edu
I quess I shouldn't have 127.127.1.0 in there, so that ntpd will look outside my system. Wait ... I've removed the line "server 127.127.1.0" from /etc/ntp.conf, restarted ntpd, waited about 4 minutes, and now my system time appears to be correct. Problem solved; thanks loads.
 
Old 09-13-2009, 06:40 PM   #6
michaelk
Moderator
 
Registered: Aug 2002
Posts: 21,501

Rep: Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110
BTW server 127.127.1.0 is a fake time server when your computer can not connect to the internet. Restarting ntpd was probably all that was needed. At least its working now.
 
Old 09-13-2009, 10:09 PM   #7
TB0ne
LQ Guru
 
Registered: Jul 2003
Location: Birmingham, Alabama
Distribution: SuSE, RedHat, Slack,CentOS
Posts: 23,816

Rep: Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975Reputation: 6975
Quote:
Originally Posted by GregLee View Post
Oh, so that's what "*" means. But I don't know what is the problem with the last server listed. Here are the servers requested in ntp.conf:
Code:
server 0.fedora.pool.ntp.org
server 1.fedora.pool.ntp.org
server 2.fedora.pool.ntp.org
server 127.127.1.0
server ntp.hawaii.edu
I quess I shouldn't have 127.127.1.0 in there, so that ntpd will look outside my system. Wait ... I've removed the line "server 127.127.1.0" from /etc/ntp.conf, restarted ntpd, waited about 4 minutes, and now my system time appears to be correct. Problem solved; thanks loads.
These aren't VM servers by any chance, are they?? Linux guests under VMware ESX had a bug, causing time to drift quickly. It would eventually get so far out of whack, that NTP would die, or go back to local-reference.

VMware and/or RedHat (can't remember right now), released a patch that supposedly fixed it.
 
Old 09-14-2009, 06:36 AM   #8
michaelk
Moderator
 
Registered: Aug 2002
Posts: 21,501

Rep: Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110Reputation: 4110
I do not think that VM servers are allowed in the ntp pool but I could be wrong.
 
Old 09-14-2009, 11:22 AM   #9
Shadow_7
Senior Member
 
Registered: Feb 2003
Distribution: debian
Posts: 4,137
Blog Entries: 1

Rep: Reputation: 873Reputation: 873Reputation: 873Reputation: 873Reputation: 873Reputation: 873Reputation: 873
I don't do anything that requires that sort of constant syncing. I just run "ntpdate time-b.nist.gov" every so often and that is good enough. I'm rarely more than five minutes off if I do that at least once a month. Baring any sort of power outage, heavy media processing / game playing, or other things that toys with the system clock. One caveat is that I do have to lower my network usage (dial-up connection) to have it work.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
NTP time sync with windows 2000 AD time csghosh Linux - Enterprise 7 02-24-2012 03:46 PM
ntp drift file in /etc/ntp instead of /var/lib/ntp - suggestion for a patch in Slack niels.horn Slackware 16 05-07-2009 07:35 PM
time synchronization - NTP tractng Linux - Newbie 1 04-02-2008 08:28 PM
NTP Server giving central time instead of eastern time wjleon Linux - Networking 3 11-01-2007 04:04 PM
debian: Get time from ntp (network time protocol) servers checkmate3001 LinuxQuestions.org Member Success Stories 0 09-30-2007 06:36 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Software

All times are GMT -5. The time now is 08:57 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration