On Thu, 5 May 2011 23:43:25 +0200 Lorens Kockum <dovecot.f...@tagged.lorens.org> articulated:
> On Thu, May 05, 2011 at 07:54:50PM +0100, Spyros Tsiolis wrote: > > > > Seriously ? > > Yes, Timo was (of course) both serious and correct. > > ntpdate takes one or more NTP servers as parameters, and sets > your server's time to match that of the NTP servers. That may > well cause a jump, even a massive jump. > > ntpd takes a list of NTP servers in its configuration file, > and uses them to make continual small adjustments. I seem to > remember that in some cases it is even capable of adjusting the > speed of your system clock according to its measurements. If the > difference is too great it will refuse to function and exit with > an error. > > The usual way is to run ntpdate with -b option once at boot > (just after the network comes up and long before things like > dovecot and MTAs get started), and then start up ntpd. > > The other way is to run ntpdate frequently, against an NTP > server you trust. It's not as good, but sometimes there may be > objections against running daemons, and if you're aiming at a > well-behaved NTP server the jumps should be minimal. > > When running ntpd, the essential thing is to check that > it's actually doing its job. You do that with the command > "ntpdc". That will drop you to a prompt. The essential commands > are > > sysinfo > peers > server x.x.x.x > sysinfo > quit > > sysinfo should give your stratum as somwhere between 3 and 5 (if > it's less you're probably doing something wrong, and if it's 16 > you're not synchronized). peers should give one * sign in the > first column and some number of + signs. > > After that overview, man ntpdate, man ntpd, and google :-) > > HTH. On a FreeBSD machine, putting the following two lines into the "/etc/rc.conf" file will cause "ntp" to be started and force it to synchronize the time regardless of how far out of sync it actually is. ntpd_enable="YES" # Start time server ntpd_sync_on_start="YES" # Synchronize on start Of course, you still need to have a default ntp.conf file. -- Jerry ✌ dovecot.u...@seibercom.net Disclaimer: off-list followups get on-list replies or get ignored. Please do not ignore the Reply-To header. __________________________________________________________________
