nanog mailing list archives
Re: Linux: concerns over systemd adoption and Debian's decision to switch
From: Stephen Satchell <list () satchell net>
Date: Wed, 22 Oct 2014 23:51:18 -0700
On 10/22/2014 08:20 PM, Simon Lyall wrote:
On Wed, 22 Oct 2014, Miles Fidelman wrote:And maybe, you should check out some of the upstream bug reports re. systemd interactions with NTP.If you think the current situation is all good then maybe you should look at other bugs for ntp. eg this one I that affected me with Ubuntu Disktop. They only run time syncing when the network is bounced so if you have a stable network then your machine will never sync: https://bugs.launchpad.net/ubuntu/+source/ntp/+bug/1178933 Note that the importance of this has been set to "wishlist".
Looking at the ticket you submitted, I see this statement:
On Ubuntu 12.04 desktop, in System Settings > Time & Date, when the time is set to update Automatically from Internet it syncs once but then drifts out over a period of days. In Syslog I can see that ntpdate is called on boot but is never called again.
I'm a long-time user of NTP, and what you are asking for is a no-good way of doing things. What you are supposed to do is use the ntpdate(8) utility *ONCE* on boot to initially set the system clock, then you have ntpd(8) running to do two things for you: sync up to one or more time sources, and discipline the local clock. What is "discipline the local clock?" This is the process of determining the *exact* frequency of the crystal clock in your local computer, and tuning your local clock hardware so that local real time is in sync with the world. This is because the accuracy of the crystal is specified to be rather loose (hundreds of parts per million), but the relative accuracy of a crystal is actually within tens of parts or even single-digit parts per million. So if you can measure the drift, you can in software compensate for it so you get a true-chimer. That's what the ntpd daemon does. Now, what is supposed to start the ntpd daemon in Ubuntu? DHCP has no significant effects on the filters used in ntpd(8). I didn't have any problem getting this to work "the right way" on Slackware, Red Hat, and Debian. It works "out of the box" with Fedora and CentOS, to the point that I don't even think much about it other than in the GUI to point to my local time source on system install. It even works with the Ubuntu 8.04.4 LTS server that was forced down my throat a few years back, which I'm in the process of trying to retire in favor of a CentOS 6.5 server implementation. (At least THAT Ubuntu-loving sysadmin is gone now.) What happens on your box when you do "/etc/init.d/ntp start"? And how frequently do you reboot your box? It sounds like it's up all the time, which means the local clock can be trimmed very accurately indeed. That's the SERVER way of running a time synchronization. So it would appear that you have a quarrel with GUI support, not with NTP itself.
Current thread:
- Re: Linux: concerns over systemd adoption and Debian's decision to switch, (continued)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Miles Fidelman (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Jeffrey Ollie (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Miles Fidelman (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Jeffrey Ollie (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Joe Loiacono (Oct 23)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Jay Ashworth (Oct 24)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Chris Adams (Oct 24)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Jay Ashworth (Oct 27)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Miles Fidelman (Oct 27)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Simon Lyall (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Stephen Satchell (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Simon Lyall (Oct 23)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Doug Barton (Oct 23)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Valdis . Kletnieks (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Jeffrey Ollie (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Matt Palmer (Oct 23)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Robert Kisteleki (Oct 23)
- Message not available
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Larry Sheldon (Oct 23)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Jay Ashworth (Oct 24)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Stephen Satchell (Oct 22)
- Re: Linux: concerns over systemd adoption and Debian's decision to switch Israel G. Lugo (Oct 22)