RE: Using non-PPS receiver for ntpd?

[Stein, Josh]

It looks like a permissions issue is at the heart of this right now:

ntpshmmon
WARNING: could not open SHM(0): Permission denied(13)
WARNING: could not open SHM(1): Permission denied(13)
ntpshmmon: version 3.22
#      Name  Seen@                 Clock                 Real                 L 
Prc

I'll re-check who is running gpsd and ntpd to make sure it is indeed root and 
try again...



-----Original Message-----
From: Greg Troxel <gdt@lexort.com> 
Sent: Wednesday, June 9, 2021 10:48 AM
To: Stein, Josh <josh@anl.gov>
Cc: gpsd users <gpsd-users@nongnu.org>
Subject: Re: Using non-PPS receiver for ntpd?


"Stein, Josh" <josh@anl.gov> writes:

Run 'ntpshmon' and see if you are getting reports.

Restart ntpd after having started gpsd.  I'm not sure this is or should be 
necessary, but...

> But the output from ntpq doesn't look good to (my untrained) eye:
>
> ntpq -p
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
>  us.pool.ntp.org .POOL.          16 p    -   64    0    0.000    0.000   0.001
>  SHM(0)          .GPS.            0 l    -   64    0    0.000    0.000   0.000
>
> I'm currently focusing on the "pool" entry of the ntp.conf as a 
> possible culprit for my (apparent) problem. As you stated, this is not 
> a gpsd specific issue so that debugging path likely does not belong 
> here on this mailing list.

The pool entry is from default config, and tells ntpd to look up servers to use 
and add them.  With no internet, that won't work, but that should be ok.  That 
status line won't really change.

The problem is that ntpd is not seeing data from shared memory.