Problem setting up NTP Time Sync

[ldb20151]

After working through my GPS initialization issues in 1698, I convinced myself I was ready to proceed with installation of ntpsec. Installation appeared to proceed with no issues. I saved and have reviewed the log -- all looks OK from my perspective.
When I proceed to configure: /etc/ntpsec/ntp.conf I receive a "permission denied" error. Just to see where the system was I went ahead and tried to validate the time sync setup with ntpq -p I received a complex printout -- not sure how to interpret it. It appeared to show time relative to other internet sources but I can't judge good vs bad with what I know.
Questions: 1) How do I interpret the validation info to tell if all is working correctly? If "remote" and "refid" columns refer to compared sources, wouldn't I expect to see GPS as one of these sources? I also don't see any reference to 127 in either column, though there do appear to be .POOL. and other sources listed. I'm inserting below as best I can -- sorry for the poor formatting.
remote refid st t when poll reach delay offset jitter

0.debian.pool.n .POOL. 16 p - 256 0 0.0000 0.0000 0.0001
1.debian.pool.n .POOL. 16 p - 64 0 0.0000 0.0000 0.0001
2.debian.pool.n .POOL. 16 p - 64 0 0.0000 0.0000 0.0001
3.debian.pool.n .POOL. 16 p - 64 0 0.0000 0.0000 0.0001
#time3.lshiy.com 218.73.139.35 2 u 39 64 377 212.1545 17.2951 42.3735
-t1.time.gq1.yah 98.137.249.214 2 u 49 64 377 77.4410 26.5090 41.4023
+23.150.40.242 204.9.54.119 2 u 8 64 167 46.0108 19.3603 28.3449
+coco.presumed.n 173.73.96.68 2 u 10 64 377 10.0497 53.6671 27.5131
-144.202.41.38.v 23.150.41.122 5 u 42 64 373 34.2284 58.9533 36.6977
+66.205.249.28 204.9.54.119 2 u 43 64 177 27.2700 54.9055 33.7440
#104-167-215-195 128.138.140.44 2 u 178 64 64 43.3153 -50.8364 58.5879
#static-72-87-88 185.125.190.56 3 u 36 64 377 25.2096 59.1146 34.3922
+time2.tritan.ho 169.117.81.12 2 u 28 64 321 39.6482 -50.2633 66.1864
#connected.by.fr 10.1.105.4 2 u 32 64 377 100.7847 58.9414 30.3287
+mailhost.netads 206.108.0.131 2 u 39 64 377 15.7032 17.0581 40.9586
-ntp.speculation 128.9.176.30 2 u 42 64 377 70.4508 73.4844 50.8602
-h96-60-160-227. .PPS. 1 u 35 64 357 87.2635 6.7489 38.6811
*t1.time.bf1.yah 98.139.133.62 2 u 27 64 377 18.7616 17.5688 32.0928
+sensei.ruselabs 128.138.140.44 2 u 37 64 377 68.3962 14.4671 27.7650
#50.218.103.254 132.163.96.1 2 u 149 64 64 21.1707 18.0302 67.8268

2. Why did I get permission denied when trying to configure? Since I'm internet connected, do I need to worry about configuration?
   As always, help is appreciated.
   -Larry

[aaronwmorris]

You will need to edit the ntp config file via sudo. The output above just means you are ntp syncing using ntp hosts on the Internet, which is expected. Once you add the configuration in the GPS wiki page, you should see something like this:

$ ntpq -p
     remote                                   refid      st t when poll reach   delay   offset   jitter
=======================================================================================================
xSHM(0)                                  .GPS.            1 l   14   16  377   0.0000 -67.2402   1.5992
 0.ubuntu.pool.ntp.org                   .POOL.          16 p    -   64    0   0.0000   0.0000   0.0005
 1.ubuntu.pool.ntp.org                   .POOL.          16 p    -   64    0   0.0000   0.0000   0.0005
 2.ubuntu.pool.ntp.org                   .POOL.          16 p    -  256    0   0.0000   0.0000   0.0005
 3.ubuntu.pool.ntp.org                   .POOL.          16 p    -  256    0   0.0000   0.0000   0.0005
-alphyn.canonical.com                    132.163.96.1     2 u   97 1024  377  50.1493   7.4558   1.8710
+149.28.61.105.vultrusercontent.com      208.113.130.146  3 u  394 1024  377  43.2707   6.7218   1.7831
*99-28-14-242.lightspeed.iplsin.sbcgloba ....             1 u  563 1024  375  50.5627   1.4358   3.8964
+time.tritan.host                        169.117.81.12    2 u  304 1024  377  39.0295   6.4774   2.1746
-pool-173-71-68-71.cmdnnj.fios.verizon.n .PPS.            1 u  248 1024  377  53.3408  11.5682   3.6370
-ntp4.glypnod.com                        129.6.15.27      2 u  431 1024  377  60.4248   8.4087   1.1600

[ldb20151]

I edited the config file as described in the wiki. The first time the file was completely blank and that surprised me. I added the new text and things didn't work correctly so I went back to check my entries and noticed the file had significant config text that I didn't add -- my entries were gone. Not sure what I did there but I corrected the ntp.conf file per the wiki, restarted the NTP server and now I'm getting the following output from ntpq -p:
REMOTE Refid st t when poll reach delay offset jitter
xSHM(0) .GPS. 1 l 1 16 377 0.0000 -655.277 20.9238
Everything looks good to me except offset and jitter appear larger than I'd expect. I guess this may be due to the fact that the antenna is with me here inside the workshop. Just can't reach a clear view of sky and too cold to work outside right now. Still, this seems like a pretty big offset and I'm concerned ntp isn't sync'ing properly. FYI I did not "uncomment" the PPE lines in the ntp.conf file so that feature is not enabled. Do I need that level of precision for the camera and would it help the delay numbers? Just a thought.
I still can't get gnome or scrot to work on this system, so again I'm sorry for the lack of a screen shot. The other parameters are in line with the GPS but 2+ orders of magnitude smaller delay values. Next largest jitter is about 10.7.
Is this good to go so I can move to next steps or are there other checks I should do first?

[aaronwmorris]

You definitely do not need the PPS signal. That is only really useful for people who need high level precision for occlusions or eclipses, etc.

It is odd that /etc/ntpsec/ntp.conf was blank. This what my system with GPS looks like (excluding comments):

driftfile /var/lib/ntpsec/ntp.drift
leapfile /usr/share/zoneinfo/leap-seconds.list

tos maxclock 11

### I only added the following two lines
server 127.127.28.0 minpoll 4 maxpoll 4 prefer
fudge 127.127.28.0 refid GPS stratum 1
###

pool 0.ubuntu.pool.ntp.org iburst
pool 1.ubuntu.pool.ntp.org iburst
pool 2.ubuntu.pool.ntp.org iburst
pool 3.ubuntu.pool.ntp.org iburst

server ntp.ubuntu.com

restrict default kod nomodify nopeer noquery limited

restrict 127.0.0.1
restrict ::1

[ldb20151]

Thank you for the ntp.conf example. The bottom line, I think I solved the time sync issue (super high delay/jitter). I'm still not able to verify -- don't know how -- AllSky is using the data. Maybe these checks are all that's needed?

The details....
First, regarding the mysterious empty /etc/ntpsec/ntp.conf file at my first edit. You're correct, that was entirely my mistake. I had a typo the first time I attempted to edit the file. To my surprise, instead of throwing an error and telling me that my fat-fingered file name didn't exist, the nano editor just opened a new, empty file. When I attempted to "re-open" it later to double check my entries, I typed the correct file name, saw the needed edits were missing ('cause this was the first time I had accessed the correct file), added them and things started working, albeit with the higher than expected time delay. At this point, I still have an unneeded "typo file" at the same location as the correct ntp.conf file. I don't know how to delete it so for now I'm ignoring it. Is this going to hurt anything? How can I delete it without messing up other files in this area? So far, it doesn't seem to be having an adverse effect.

Regarding the delay, for reasons I can't explain, the ntp.conf text was missing the line "server ntp.ubuntu.com" -- in my case "server ntp.debian.com", I think since those are the default pool references. Seems they should be the same so I made the adjustment and its working. There was also an extra line I don't recall, so I removed it to match your file. Once I adjusted the ntp.conf file to match yours (except for the debian reference) and reset the NTP, my GPS time fell nicely in line with your example.

I have not yet checked to see if AllSky is actually using the GPS time and locations data -- is there a way to verify that other than ntpq -p?
Thx much!

[aaronwmorris]

ntpq -p is really the only method of validating that I am aware of.

[ldb20151]

I've gone through everything and finally have ntpq -p producing the correct response. Once in the camera application and signed in to indi-allsky, I went to the systems/time tab and see the following:
NTP Available
False
NTP Enabled
False
NTP Synchronized
True
RTC Available
False
Given I'm using onboard GPS, shouldn't all of these read "false"? I've gone back over the steps to install/enable GPS and can't find any issues. We are having very heavy rain today. The GPS is dropping out once in a while but says it's locked now. Am I understanding this correctly? If so, do you have any suggestions on where I should look to resolve the problem?
I must be getting close. I sure hate to give up on it now but this has proven to be harder than I expected.

[aaronwmorris]

This is kind of to be expected. These indicators are from systemd and you are bypassing the systemd timesync configs. I am surprised it detected the system was NTP synchronized.