[BUGS] ntpdate/ntpd at startup (was: Dovecot not starting on startup)

[Jerahmy Pocott]

On 24/04/2008, at 9:59 PM, Andrew Reilly wrote:

> I thought that ntpd didn't make the clock go backwards (which  
> ntpdate -b can), it just goes forwards more slowly than usual for a  
> while, if necessary.

Unless you set the -g option, in which case it does, once.


> And we're talking about servers here: it's not as though they spend  
> a lot of their time off, and even when they do there's usually a  
> battery-powered clock of some sort that stops things from getting  
> too out-of-whack in the mean time.

It's rarely an issue, but if for what ever reason the server goes down  
it becomes an issue for two reasons:

1) If you don't set the -g option ntpd will not set the clock at all  
in the case where the time difference is large, it will just  
terminate. Leaving your clock out of sync.

2) Setting the -g option will make ntpd work, but then brings the  
possibility of other services breaking.

In either case its going to require manual intervention to fix. With  
ntpdate -b no manual intervention is required, ntpd will be happy and  
the clock will be set prior to anything else starting. Removing  
ntpdate -b and not supplying the same functionality anywhere else  
seems like a bad idea, but because it is rare, many people probably  
haven't realised the impact of it yet..