Draft Stratum 1 Microserver HOWTO is up

[Clark B. Wierda]

I just finished a pass using a GR-601W and adjusting as needed.  I will
only address the items that still apply and that are not already mentioned
by Hal.

On Sat, May 21, 2016 at 12:03 AM, Hal Murray <hmurray at megapathdsl.net>
wrote:

>
> > A micro-SD card. 1GB is minimal. 4GB is plenty.
>
> I decided 4 GB wasn't big enough, but I build gpsd, NTPsec, and NTP
> classic,
> and keep lots of log files.  It felt like builds were slowing down, but
> maybe
> I was just getting impatient.  I don't have hard numbers.  I think SD cards
> work better if they are not close to full.
>
> The Rasbian-lite image is 1.3 GB.  My 1 GB microSD failed before it ran
out of space, so I was not able to test this explicitly.

Also, after finishing the process, the space used was 1.3 GB.  I started
with a fresh install and only did the builds mentioned in the manual steps.


>
> You describe assembling the board and HAT before inserting it into the
> case.
> Have you tried that?  I don't think it will work.  The board has to go in
> tilted, HMDI side first.  The HAT gets in the way of the tilt.
>
> You might mention the DogBone case.
>


GeauxRobot Dogbone Case for RPi 3 (and others)
<http://www.amazon.com/gp/product/B00BR1IJUO/ref=s9_acsd_hps_bw_c_x_3>


>
> > device will likely be /dev/sdd
>
> Mine works out to be sdd, but I think that depends on several things.  I
> have
> a second hard disk that gets sdb, and I use a multi-slot USB to small-card
> adapter that sets up sdc, sdd, sde, and sdf.  The SD slot just happens to
> be
> sdd.
>
>
It was /dev/mmcblk0 using the built-in card reader on my laptop.


>
> > There is a different, non-HAT Adafruit product, the "Ultimate GPS
> Breakout
> > Board", that also uses GPIO18/P1-12. This may be a source of confusion if
> > you read some of the references in this document.
>
> The breakout board doesn't know anything about GPIO pins.  You are probably
> thinking of some writeup that cloned the Uputronics pins.
>
>
There is a write-up on the Adafruit site that wires the PPS to GPIO18.


> > # Known Stratum 1 servers with excellent quality and connectivity.
> > server 199.102.46.72 iburst     # tock.usshc.com
> > server 149.20.64.28 iburst      # clock.isc.org
> > server 17.254.0.49 iburst       # tick.apple.com
>
> This gets complicated.  It's also important.
>
> In general, you don't want to wire a name or address into gear that you
> don't
> directly control without the owner's permission.  If you do get their
> permission, you want to set things up so that they can easily and cleanly
> revoke that permission.  This holds for things like anti-spam black lists
> as
> well as NTP servers.
>
> One way to revoke permission is to insert a layer of indirection in the
> DNS,
> a cname.  Deleting that cname (or the landing name) breaks things and stops
> the traffic.  (It may shift the load to the DNS servers.)
>
> The wikipedia page on NTP abuse is very good.
>   https://en.wikipedia.org/wiki/NTP_server_misuse_and_abuse
> I think Dave Plonka's writeup should be required reading for any computer
> science degree.
>
> On top of all that, the connectivity is only good if you are located near
> the
> servers.
>

We may want to just use the NTP Pool (and get a vendor code which addresses
issue Hal mentions).  That should be good enough for sanity checking.
Something like:
server 0.ntpsec.pool.ntp.org
server 1.ntpsec.pool.ntp.org
server 2.ntpsec.pool.ntp.org (this one will also support IPv6)

We could also mention that the ntpsec could be replaced with their region
(us, europe, ...).


>
> > GPS Serial data reference (NTP0) [Second one]
>   NTP0 => NTP1
>
> > Internet time servers
>
> There is no section of the ntp.conf labeled "Internet time servers"
>
> Your ntp.conf doesn't enable any logging.
>
>
> > # ntpsec/build/main/ntpq/ntpq -p
>
> The printout doesn't match the ntp.conf you just described.  It's still
> using
> 4 pool servers.
>
> > # cp pinup /usr/local/bin
> What's "pinup"?  Where did it come from?
>

'pinup' is downloaded by the automated script.  Also, in that script, it is
expected to be in the directory above the 'ntpsec' directory with
'ntp.conf' which doesn't quite match the manual instructions.


I stopped after copying the text into the correct files and rebooting.



> > Odroid C2
>
>
I'll test this one after verifying the Adafruit HAT against the RPi2 and
the RPi3.

Clark
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