Re: Proper Method of Time Sync? (added: time server choices)
Murray Taylor [EMAIL PROTECTED] wrote: Also read this http://people.freebsd.org/~phk/dlink/ For how not to do it !! What a sorry tale! I had previously read about some of Poul's time-geek activities. So sad that his efforts should be vandalised like that. Unbelievable that some people think he should just live with it. -- John. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
RE: Proper Method of Time Sync? (added: time server choices)
Google for pool.ntp.org to find a set of NTP servers near you ... Also read this http://people.freebsd.org/~phk/dlink/ For how not to do it !! mjt -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, 16 April 2006 12:53 PM To: Pete Slagle; freebsd-questions@freebsd.org Subject: Re: Proper Method of Time Sync? At 06:41 AM 4/15/2006, Pete Slagle wrote: ntpd_flags=-A -p /var/run/ntpd.pid Just curious, why disable authentication (with -A)? 'Cause that's how it's shown in the quick dirty example in The Handbook or FAQ or something ;) I didn't find much other info on it, but I figured you had to coordinate it on both ends, and it was overkill for my needs. Should I mess with it? -Wayne ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] ***This Email has been scanned for Viruses by MailMarshal.*** --- The information transmitted in this e-mail is for the exclusive use of the intended addressee and may contain confidential and/or privileged material. Any review, re-transmission, dissemination or other use of it, or the taking of any action in reliance upon this information by persons and/or entities other than the intended recipient is prohibited. If you received this in error, please inform the sender and/or addressee immediately and delete the material. E-mails may not be secure, may contain computer viruses and may be corrupted in transmission. Please carefully check this e-mail (and any attachment) accordingly. No warranties are given and no liability is accepted for any loss or damage caused by such matters. --- ***This Email has been scanned for Viruses by MailMarshal.*** ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
[EMAIL PROTECTED] wrote: rc.conf: ntpd_sync_on_start=YES# Sync time on ntpd startup, even if offset is high ntpd_flags=-A -p /var/run/ntpd.pid Just curious, why disable authentication (with -A)? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
At 06:41 AM 4/15/2006, Pete Slagle wrote: ntpd_flags=-A -p /var/run/ntpd.pid Just curious, why disable authentication (with -A)? 'Cause that's how it's shown in the quick dirty example in The Handbook or FAQ or something ;) I didn't find much other info on it, but I figured you had to coordinate it on both ends, and it was overkill for my needs. Should I mess with it? -Wayne ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Proper Method of Time Sync?
i have read about 2 methods to sync the time on a freebsd box. 1) add these entries to /etc/rc.conf: ntpdate_enable=YES ntpdate_flags=us.pool.ntp.org ... and let the system do a one-time sync at bootup, and rely on this single method for timesync. 2) add this entry to /etc/rc.conf ntpd_enable=YES add the file with these contents to /etc/rc.conf: server us.pool.ntp.org driftfile /var/db/ntp.drift restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap so, i have a workstation and a server, which i originally did method 1 on, but soon enough, time drifted quite a bit. so i switched it to the 2nd method, and they appear to be sync'd perfectly. a third box i set up, i did only method 2, and this one did not stay synced at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this box straightend up. are both methods required for proper time syncronization, or can one rely only on the ntpd method? thanks, Jonathan Horne ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
i have read about 2 methods to sync the time on a freebsd box. 1) add these entries to /etc/rc.conf: ntpdate_enable=YES ntpdate_flags=us.pool.ntp.org ... and let the system do a one-time sync at bootup, and rely on this single method for timesync. 2) add this entry to /etc/rc.conf ntpd_enable=YES add the file with these contents to /etc/rc.conf: server us.pool.ntp.org driftfile /var/db/ntp.drift restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap so, i have a workstation and a server, which i originally did method 1 on, but soon enough, time drifted quite a bit. so i switched it to the 2nd method, and they appear to be sync'd perfectly. a third box i set up, i did only method 2, and this one did not stay synced at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this box straightend up. are both methods required for proper time syncronization, or can one rely only on the ntpd method? thanks, Jonathan Horne Sorry, Typo: 2) add this entry to /etc/rc.conf ntpd_enable=YES add the file with these contents to /etc/rc.conf: i meant to say add the file /etc/ntp.conf with these contents thanks, Jonathan Horne ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
In the last episode (Apr 14), Jonathan Horne said: i have read about 2 methods to sync the time on a freebsd box. 1) add these entries to /etc/rc.conf: ntpdate_enable=YES ntpdate_flags=us.pool.ntp.org ... and let the system do a one-time sync at bootup, and rely on this single method for timesync. 2) add this entry to /etc/rc.conf ntpd_enable=YES add the file with these contents to /etc/rc.conf: server us.pool.ntp.org driftfile /var/db/ntp.drift restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap so, i have a workstation and a server, which i originally did method 1 on, but soon enough, time drifted quite a bit. so i switched it to the 2nd method, and they appear to be sync'd perfectly. a third box i set up, i did only method 2, and this one did not stay synced at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this box straightend up. are both methods required for proper time syncronization, or can one rely only on the ntpd method? ntpd takes a while to sync up and by default won't adjust the clock if it's more than 1000 seconds off, so it's a good idea to enable ntpdate as well. You don't need the ntpdate_flags variable; the startup script will grab server names out of /etc/ntp.conf . -- Dan Nelson [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
Jonathan Horne wrote: [ ...ntpdate versus ntpd... ] so, i have a workstation and a server, which i originally did method 1 on, but soon enough, time drifted quite a bit. so i switched it to the 2nd method, and they appear to be sync'd perfectly. a third box i set up, i did only method 2, and this one did not stay synced at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this box straightend up. are both methods required for proper time syncronization, or can one rely only on the ntpd method? You can use both together quite safely, but usually only the second is needed. If ntpd can't correct the clock by itself, that generally means it's off my more than 2000 seconds or whatever the sanity-check threshold is, and needs a manual correction or one-time use of ntpdate before ntpd will keep things sane from there. -- -Chuck ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
Jonathan Horne wrote: i have read about 2 methods to sync the time on a freebsd box. 1) add these entries to /etc/rc.conf: ntpdate_enable=YES ntpdate_flags=us.pool.ntp.org ... and let the system do a one-time sync at bootup, and rely on this single method for timesync. 2) add this entry to /etc/rc.conf ntpd_enable=YES add the file with these contents to /etc/rc.conf: server us.pool.ntp.org driftfile /var/db/ntp.drift restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap so, i have a workstation and a server, which i originally did method 1 on, but soon enough, time drifted quite a bit. so i switched it to the 2nd method, and they appear to be sync'd perfectly. a third box i set up, i did only method 2, and this one did not stay synced at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this box straightend up. are both methods required for proper time syncronization, or can one rely only on the ntpd method? If the time is too far out of sync when ntpd starts, it will not correct it. Look at the -g option which allows to it make a major correction once. That functionality is designed to replace ntpdate, but ntpd can take a long time to sync the time first time, so it can make sense to use both methods. ntpdate will set the date fairly accurately, fairly quickly and when ntpd comes on-line it will smooth out the edges and keep you on track. For a very long time, ntpdate manual page has described it as about to disappear - but since it doesn't go away I think that comment is somewhat meaningless and confusing. I'm fairly sure there was recent work on the rcNG scripts for ntpdate to make it operate better with ntpd (pick up the list of ntpd servers automatically if none were specified specifically for ntpdate). GIven that, I think the this program will go away comment in the man page is plain wrong. It appeared mid 4.X I believe, and still appears in 6.0 and apparently 7-current if the online man pages can be believed. Perhaps someone who knows, could clarify. --Alex ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
At 11:40 AM 4/14/2006, Jonathan Horne wrote: i have read about 2 methods to sync the time on a freebsd box. ...i have a workstation and a server, which i originally did method 1 on, but soon enough, time drifted quite a bit. so i switched it to the 2nd method, and they appear to be sync'd perfectly. a third box i set up, i did only method 2, and this one did not stay synced at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this box straightend up. First off, ntpdate is obsolete, and will be retired sometime in the future. Its functionality has been incorporated into ntpd. I think your problem is a limit in ntpd that's enabled by default. There is a limit on how large a correction ntpd will make at one time, even at boot up. ntpdate isn't that picky and always just syncs, even if the offset is large. Try some rtfmp on ntpd, ntpdate and ntpd.conf. I run ntpd on one server, with a flag (-g) set to always sync, eg: rc.conf: ntpd_sync_on_start=YES# Sync time on ntpd startup, even if offset is high ntpd_flags=-A -p /var/run/ntpd.pid And ntp.conf: server rolex.usg.edu driftfile /etc/ntp.drift logfile /var/log/ntpd.log restrict 208.62.177.32 mask 255.255.255.224 nomodify notrap My other servers and desktops are similarly configured, but sync off the first server. Be sure to specify the driftfile; ntpd will learn how fast or slow your clock is and record it, so it can apply corrections when/if an internet connection isn't up. Be sure the file exists and has some number. You can initialize with: echo 0 /var//db/ntp.drift ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
RE: Proper Method of Time Sync?
At 11:40 AM 4/14/2006, Jonathan Horne wrote: i have read about 2 methods to sync the time on a freebsd box. ...i have a workstation and a server, which i originally did method 1 on, but soon enough, time drifted quite a bit. so i switched it to the 2nd method, and they appear to be sync'd perfectly. a third box i set up, i did only method 2, and this one did not stay synced at all. after i manually ran 'ntpdate -v -b us.pool.ntp.org', this box straightend up. Also, you should consider using one of the NTP server pools instead of hard-coding one. This gives you one of several low-stratum servers each time you boot and distributes the load for the time servers: server pool.ntp.org If you're in the US, you could a regional server with: server us.pool.ntp.org In the UK: server uk.pool.ntp.org Tony ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
On Friday 14 April 2006 16:53, Dan Nelson wrote: ntpd takes a while to sync up and by default won't adjust the clock if it's more than 1000 seconds off, so it's a good idea to enable ntpdate as well. What bothers me about that is that ntpdate uses a single server to determine the time. I can't recall the reference, but I recently read a horror story where someone synched off a timeserver that had been set to 2038 for testing purposes. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Proper Method of Time Sync?
From: RW [EMAIL PROTECTED]
On Friday 14 April 2006 16:53, Dan Nelson wrote:
ntpd takes a while to sync up and by default won't adjust the clock if
it's more than 1000 seconds off, so it's a good idea to enable ntpdate
as well.
What bothers me about that is that ntpdate uses a single server to determine
the time. I can't recall the reference, but I recently read a horror story
where someone synched off a timeserver that had been set to 2038 for testing
purposes.
Feed it several server names and try it. Use the -q option so it will not
attempt to modify time and the -v option to see what it does in more
detail.
{^_^}
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