So ntpdate is no longer present past CentOS 7.
Many times people want "internal" NTP servers - not opening firewalls to allow external pool.ntp.org kind of stuff.
ntpdate was "nice" in that I could just run once a day as "ntpdate name" and all good. Is there a similar client for CentOS 8 ? I saw chrony - but does not seem to be a command line command and I would also have to edit a file - Both are not desirable.
Just looking for a simple - flexible command like I have been using "ntpdate name" for CentOS 8.
Thanks,
Jerry
There is a command-line option for chronyd which runs once, sets the time and exits.
# chronyd -q
I run chrony as a daemon on all my systems. One system is a server to everything else that is internal. The server is the only one that goes outside. It works well. The initial setup is basically a one-time deal. After that it can be pretty much ignored.
On Wed, Dec 2, 2020 at 11:17 AM Jerry Geis jerry.geis@gmail.com wrote:
... ntpdate was "nice" in that I could just run once a day as "ntpdate name"
the problem with that sort of time sync is that if your systems clock is running fast, then those once a day time syncs cause the clock to be set BACK a few seconds or whatever (in bad cases a few minutes).
I have always run ONE primary ntp server on my internal network, given it firewall access to the ntp ports, then had all my other systems ntp sync off that one server. This only requires a single port OUTBOUND connection from that one server. I generally avoid the 'pool' servers, and instead manually chose a set of regional stratum I or II NTP servers that are listed as being offered to the public.
On Wed, Dec 2, 2020 at 1:26 PM John Pierce jhn.pierce@gmail.com wrote:
the problem with that sort of time sync is that if your systems clock is running fast, then those once a day time syncs cause the clock to be set BACK a few seconds or whatever (in bad cases a few minutes).
Modern chrony that Bill Gee pointed out does a skew unless you manually tell it to step the time into sync.
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/htm...
Thanks everyone for the comments. So trying to use the new "chronyc/d"
So trying a couple things with chronyc
chronyc sources 210 Number of sources = 5 MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^* time.cloudflare.com 3 10 377 220 -481us[ -503us] +/- 17ms ^- zeit.arpnetworks.com 2 9 377 452 -1083us[-1104us] +/- 100ms ^- lofn.fancube.com 2 10 377 851 -1833us[-1854us] +/- 64ms ^- ntp3.junkemailfilter.com 2 9 377 227 -937us[ -959us] +/- 76ms ^- b.st1.ntp.br 1 6 377 56 -2300us[-2300us] +/- 79ms
NONE of the above are listed in /etc/chrony.conf
Then I tried "chronyc add server pool.ntp.porg" and ran "chronyc sources" again and my server was not added ?
I am trying to use the command line chronyc - to "add" the server I want - also wish there was an EASY way to clear the server list. Have not seen that though.
What I need is a way to add the server i want - list the server to make sure my server is in the list - and remove servers I dont want (or all).
Thanks,
Jerry
What IS in your chrony.conf file?
"pool.ntp.org" is not a single server. It is a collection of several dozen. When you specify a pool of servers for chrony, it will pick 4 mostly at random and use those. The four servers it chooses will change over time.
If you want to use exactly one specific server, then take the pool out of chrony.conf and add your specific server. I do not see a way for chronyc to remove servers, so it is a matter of editing the file directly and then restarting chronyd.
In my case, only my internal master server goes against a pool. All other internal systems use the internal master as their only source. Sometimes when I do "chronyc sources" on them, I see the server listed twice. After investigation I found that one is for IPv4 and the other for IPv6.
and I'm doing much the same: a Raspberry Pi running Raspbian, acts as my nameserver (instead of my ISP) and NTP server. all the systems in-house sync time from it.
On Wed, Dec 2, 2020 at 3:22 PM Bill Gee bgee@campercaver.net wrote:
What IS in your chrony.conf file?
"pool.ntp.org" is not a single server. It is a collection of several dozen. When you specify a pool of servers for chrony, it will pick 4 mostly at random and use those. The four servers it chooses will change over time.
If you want to use exactly one specific server, then take the pool out of chrony.conf and add your specific server. I do not see a way for chronyc to remove servers, so it is a matter of editing the file directly and then restarting chronyd.
In my case, only my internal master server goes against a pool. All other internal systems use the internal master as their only source. Sometimes when I do "chronyc sources" on them, I see the server listed twice. After investigation I found that one is for IPv4 and the other for IPv6.
-- Bill Gee
On Wednesday, December 2, 2020 2:00:56 PM CST Jerry Geis wrote:
Thanks everyone for the comments. So trying to use the new "chronyc/d"
So trying a couple things with chronyc
chronyc sources 210 Number of sources = 5 MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
^* time.cloudflare.com 3 10 377 220 -481us[ -503us] +/- 17ms ^- zeit.arpnetworks.com 2 9 377 452 -1083us[-1104us] +/- 100ms ^- lofn.fancube.com 2 10 377 851 -1833us[-1854us] +/- 64ms ^- ntp3.junkemailfilter.com 2 9 377 227 -937us[ -959us] +/- 76ms ^- b.st1.ntp.br 1 6 377 56 -2300us[-2300us] +/- 79ms
NONE of the above are listed in /etc/chrony.conf
Then I tried "chronyc add server pool.ntp.porg" and ran "chronyc sources" again and my server was not added ?
I am trying to use the command line chronyc - to "add" the server I want
also wish there was an EASY way to clear the server list. Have not seen that though.
What I need is a way to add the server i want - list the server to make sure my server is in the list - and remove servers I dont want (or all).
Thanks,
Jerry _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
On Wed, Dec 02, 2020 at 02:17:04PM -0500, Jerry Geis wrote:
So ntpdate is no longer present past CentOS 7.
What's wrong with the 'ntpdate' RPM?
https://centos.pkgs.org/7/centos-x86_64/ntpdate-4.2.6p5-29.el7.centos.2.x86_...
Thanks,
Jerry _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
On 02/12/2020 23:32, Brian Reichert wrote:
On Wed, Dec 02, 2020 at 02:17:04PM -0500, Jerry Geis wrote:
So ntpdate is no longer present past CentOS 7.
What's wrong with the 'ntpdate' RPM?
https://centos.pkgs.org/7/centos-x86_64/ntpdate-4.2.6p5-29.el7.centos.2.x86_...
What's wrong is that you've quoted the CentOS7 RPM, not the CentOS8 one (which doesn't exist). The OP was asking about ntpdate "past CentOS 7".
Thanks,
Jerry _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
On Thu, Dec 03, 2020 at 07:06:25AM +0000, J Martin Rushton via CentOS wrote:
On 02/12/2020 23:32, Brian Reichert wrote:
On Wed, Dec 02, 2020 at 02:17:04PM -0500, Jerry Geis wrote:
So ntpdate is no longer present past CentOS 7.
What's wrong with the 'ntpdate' RPM?
https://centos.pkgs.org/7/centos-x86_64/ntpdate-4.2.6p5-29.el7.centos.2.x86_...
What's wrong is that you've quoted the CentOS7 RPM, not the CentOS8 one (which doesn't exist). The OP was asking about ntpdate "past CentOS 7".
I apologize for misreading the subject.
On Thu, Dec 3, 2020 at 12:47 AM Jerry Geis jerry.geis@gmail.com wrote:
So ntpdate is no longer present past CentOS 7.
Many times people want "internal" NTP servers - not opening firewalls to allow external pool.ntp.org kind of stuff.
ntpdate was "nice" in that I could just run once a day as "ntpdate name" and all good. Is there a similar client for CentOS 8 ? I saw chrony - but does not seem to be a command line command and I would also have to edit a file - Both are not desirable.
Just looking for a simple - flexible command like I have been using "ntpdate name" for CentOS 8.
Thanks,
Jerry _______________________________________________
Hi,
I rebuilt ntpdate for EL8 from Fedora 33 srpm. No patching needed.
--- Lee
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Bill Gee -
Brian Reichert -
Fred -
J Martin Rushton -
Jerry Geis -
John Pierce -
Jon Pruente -
Thomas Stephen Lee