[ntp:questions] ntpd -d and ntpd -D X

David Woolley david at ex.djwhome.demon.co.uk.invalid
Sun Mar 15 11:10:36 UTC 2009

Varrun Ashok wrote:
> Hello everybody,      I have checked if ntpd is working in my BusyBox OS using
> ntpq -p and a few oher daemons. I went through the website www.ntp.org for a
> detailed documentatin on ntpd -d and ntpd -D X commands but could not find

That's normal.  For open source one is expected to use the source code 
as the reference.  For closed source code, one is expected to supply the 
results to the support person without understanding them.  Requiring 
detailed, end user, documentation for debugging output is generally seen 
as too much of an imposition on the coder, for open source, and as 
providing too much proprietary information, for proprietary code.

> any.My ntp accepts pps and synchronises time every 16 secs.There are a lot of

ntpd does not synchronise time every n seconds.  It provides information 
to the kernel that micro-adjusts the time rather more frequently than 
this.  It normally works in terms of adjusting frequency, rather than 
directly in terms of phase corrections.

> key words used in the output ntpd -d and ntpd -D 3 and i would like to know
> what each word means.Even google search did not yield great results.      I
> have been using 1 GHz P3 SBC. Soon I will shift to PXA270 ARM core SBC which
> runs at 512 MHz. Do the two daemons ntpd and ntpq depend on speed of

ntpq is not a daemon.

> processor. Are there any other processor dependencies.     Please mail me the
> appropriate links.

ntpd doesn't need a lot of processor power.  It has chip set 
dependencies, rather than processor dependencies. For Linux or FreeBSD, 
these are generally within the kernel support for ntpd, rather than ntpd 
itself.  The one possible processor dependency is that recent Intel 
architecture devices have a RDTSC instruction, to read a count of 
machine cycles, which might not exist for ARM, or might not be supported 
by the kernel software clock code for ARM.

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