[ntp:questions] Re: SHM refclock not being selected

John Ackermann N8UR jra at febo.com
Sun Mar 13 14:25:58 UTC 2005

David Schwartz wrote:

>>Should I be using the "prefer" keyword to force selection of the SHM 
>>clock?  Or is there some other trick I should be playing with this 
>    Can you post your configuration? I'm wondering if perhaps you have some 
>'restrict default' lines without the appropriate override. It may help to 
>add this:
>restrict mask
Here's my configuration file, with logging stuff, etc., trimmed for brevity:

    # /etc/ntp.conf, configuration for ntpd

    # Z3801A
    server ttl 1
    fudge time1 -0.967
    fudge refid GPS

    # PPS via linux_shm_clock
    fudge refid PPS

    server tock.febo.com
    server time-c.timefreq.bldrdoc.gov
    server ntp1.usno.navy.mil
    server ntp2.usno.navy.mil

That's it...

>>By the way -- I was getting absolutely horrendous, unusable time from this 
>>machine until I recompiled the 2.6.9 kernel with HZ=100, and selected 
>>"clock=pit" at boot time (not sure which of the two changes is making the 
>>most significant impact; I wasn't in a position to experiment through 
>>multiple reboots).
>    Now that's strange. Does this machine have one CPU or more than one? 
>What type?
It's an Athlon 2200 or thereabouts.  When I was running a 2.4 kernel, I 
had no problems but the change to 2.6 (necessitated by some other 
software that is the machine's primary reason for being) really screwed 
things up.


More information about the questions mailing list