[ntp:questions] iburst

terrypearl fxaxsxtxsxnxixpx-xbxcxaxrxdx at yahoo.com
Tue Nov 28 00:48:57 UTC 2006


Richard B. Gilbert wrote:
> terrypearl wrote:
> 
>> Hal Murray wrote:
>>
>>>> It doesn't require reboots - just shutting down daily when I am not
>>>> using the machine.
>>>
>>>
>>> That's a slightly(?) ugly case for keeping time.
>>>
>>> The problem is that the frequency of the crystal is strongly(?)
>>> temperature dependent.  If you run the machine for a while
>>> it warms up and gets the drift file setup for that temperture.
>>> When you turn it off, it cools down.  When you reboot it, the drift
>>> file is slightly(?) misleading.
>>>
>>> How much do you care about how accurate your clock is?
>>
>>
>> Just a normal user trying to keep a somewhat accurate clock. If left 
>> alone, the h/w clock can drift as much as 5 minutes in 6 months. I'm 
>> just trying to keep it a little more accurate than the wall clock 
>> running off the frequency of the local power grid.
>>
>> I finally learned about ntpd about a week ago. It had been set to run 
>> by the FC 5 installation. But the firewall prevented synch. When I 
>> finally got that worked out, my boot time went from about 1 minute to 
>> many minutes. In watching the boot messages, I discovered that ntpd 
>> was the culprit. It takes ntpd several minutes to synch during boot. 
>> Was simply trying to get that synch time down to something under 1 
>> minute. During the time I was trying to get ntpd through the firewall, 
>> someone on this newsgroup mentioned using iburst to get the synch time 
>> from minutes to seconds. Guess they had that wrong or we used 
>> different definitions of synch.
>>
>> So I guess if I want to use ntpd, I will have to live with the mnay 
>> minute boot time??
> 
> Please don't top post.

What do you mean "top post"? Never heard this term before.

> 
> It's not clear if you are talking about the time required to boot your 
> system or the time required to bring your clock into reasonably tight


> synchronization.  Does your system wait for synchronization before 
> before allowing you to run applications?  If so, that's something built 
> into your system startup and you may be able to modify the startup 
> scripts to avoid it.
> 
> Normally, ntpd should have little effect on the boot time.
> 
> As you are using it, it will take some time, perhaps as much as thirty 
> minutes, to achieve good (within +/- 20 milliseconds) synchronization.
> Both the protocol and the software were intended for full time use and 
> work best when so used.


-- 
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======================================================
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If you are always rushing towards the future,
Then you never have any past.

Terry Boldt
******************************************************
Paraphrasing Ben Franklin:

Those who sacrifice freedom for safety, have neither.

The exact quote:

They that can give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety.
   Benjamin Franklin (1706 - 1790),
   US author, diplomat, inventor, physicist, politician, & printer
   Historical Review of Pennsylvania, 1759

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