Preventing xntpd from stepping backwards.

[tarn]

This should be a simple question (but then these never are!) ....
I'm not able to find a definitive answer on to how to prevent the clock from stepping backwards on a platform that has an application which responds very adversely to the slightest reversal of time.

The platform is Sol 9 on Sun v440 kit. I have a fairly standard ntp setup (basic ntp.conf with 2 timeservers and half a dozen peers [one preferred], and a drift file [initially set to 0.0])

Can anyone offer me some advice on either a flag to set (I've thought about -x?) or a configuration that will prevent backwards slew or step.

Regards Laurie.

 

[GunnarD]

Why run ntp when you don't wan't to sync clock?

 

[tarn]

Ok sorry maybe I did not make myself as clear as I should have

Obviously in a production platform it is essential to maintain an accurate time across all platform elements to preserve amongst many "log file information" The obvious method of maintaining time is ntp, However, we have an application that baulks at the slightest hint of the time moving "backwards".

Therefore what we need to do (and this is where I'm asking for constructive comment) is, to configure ntp NOT to move backwards either by slew or step. I believe the objective is to "slow the clock until everything else in the network catches up this is probably achieved by some flag or particular ntp configuration.

I hope that answers your question and provides more info on what I'm asking?

Thanks
L.

 

[Annihilannic]

I'm with Gunnar here, it sounds like you don't want to run NTP at all. The only available method xntpd to deal with a clock that runs too fast is to slew it by making very small adjustments... if your application can't cope with that, best not run it at all, and just periodically correct the clock using ntdpate during scheduled application downtime, perhaps on a weekly basis if that can be arranged?

Annihilannic.