[sle-beta] beta5: Cannot adjust 'NTP' service when NTP was enabled in installer

[Joe Doupnik]

     For general amusement and perhaps education, the NTP problem of 
choosing amongst competing time givers is known as the Byzantine 
Generals Problem. The situation is a group of Generals/time givers offer 
their views, but some may not be truthful (are traitors) and ought to be 
excluded from the group. The first step in a solution is to form a 
majority group (a quorum, a concensus), and for that there needs to be 
2N+1 participants to caste out N possible non-truthful members. Then 
stratum number and optionally other measurements come into play. Thus 
for us we ought to have an odd number of time givers, a minimum of three 
and a few more than that can be better.
     Including the PC local clock amongst them biases matters if the 
local clock is far off the mark. It's presence is in case there are no 
other time givers for this machine (network problems) and yet this 
machine may offer time to other machines. Oh dear, that's an awkward 
situation if the local clock may be well off, which in turn can upset a 
site. To minimize the problem of possibly insane local machine clock 
sources have each machine reference a set of likely external sources 
located both on-site and remotely (forms overlapping meshes). Friends 
helping friends based on widely spread expertise.
     The Byzantine Generals problem arises in many kinds of 
fault-tolerant systems.
     Thanks,
     Joe D.

On 28/01/2018 11:37, Bernd Eckenfels wrote:
>
> Hello,
>
> I think the Problem here is that chrony is not part of the minimal 
> System, at least it is not installed after the Installation and I dont 
> see the package on the Installer-DVD1.
>
> The NTP Option in the installer is not only a one shot Option (which 
> seems to work) but it also offers a checkbox to start the daemon. I 
> had selected that one. The chrony config file is written with the pool 
> entry.
>
> (I pretty much prefer chrony over ntpd, it producs less Problems with 
> time warping on customer systems, so it would be good to make it a 
> essential package. Glad that SuSE catched up here)
>
> Gruss
>
> Bernd
>
> -- 
> http://bernd.eckenfels.net
>
> *Von: *Joe Doupnik <mailto:jrd at netlab1.net>
> *Gesendet: *Sonntag, 28. Januar 2018 12:16
> *An: *sle-beta at lists.suse.com <mailto:sle-beta at lists.suse.com>
> *Betreff: *Re: [sle-beta] beta5: Cannot adjust 'NTP' service when NTP 
> wasenabled in installer
>
>     There is also the step of going into systemd services and enabling 
> service NTP, at least in my experiments.
>     In the overall time keeping mix are two client-style competitors. 
> It seems to me, as some say, the wise choice would be use regular NTP 
> itself which can be both client and server, under our control. This 
> also avoids the mistake of force jumping clocks which are out of 
> synchronization, an act which can clobber cron jobs and other time 
> sensitive things. The initial setting of the local machine's time is 
> properly done by adding tag "iburst" to a server line within 
> /etc/ntp.conf. such as  server uk.pool.ntp.org iburst.  That causes 
> rapid slewing, rather than the normal more gradual one and has no jumps.
>     Nuances about choosing a time source amongst competitors is 
> another soft spot best left to the seasoned solutions of NTP proper. 
> That puzzle has been worked out over many years through much 
> experience with the protocol. Another thing to do in most cases is 
> turn off using the local clock as a time source competitor (meaning 
> comment out the lines in /etc/ntp.conf saying   server 127.127.1.0   
> and   fudge 127.127.1.0 stratum 10).
>     Thanks,
>     Joe D.
>
> On 28/01/2018 00:31, Bernd wrote:
>
>     Hello,
>
>     If I install beta5 with no registration/packages and select under
>     settings to get the time from the NTP pool the screen with the
>     timezone map shows me the right (updated) time.
>
>     But if I proceed with the installation the "Performing
>     Installation" screen (Step: "Save Installation Settings" ->
>     "Writing NTP Configuration...") shows a popup "Cannot adjust 'NTP'
>     service.". This popup does not happen when I do not enable NTP.
>     When clicking OK the installation proceeds.
>
>     Gruss
>
>     Bernd
>
>     PS: in the timezone selection the "hardware clock in UTC" does not
>     adjust the currently displayed time. It is a bit frustrating when
>     you select a timezone and the displayed current time is off by an
>     hour. Because you have to switch on the UTC mode and then go to
>     manual settings and correct the time (or turn on NTP as I did). I
>     think former versions of SLES has that "feature" as well.
>
>
>
>
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