Re: [gentoo-user] Getting a valid /etc/adjtime while using ntpd ?

[Bill Kenworthy]

On 18/03/16 05:14, Alan McKinnon wrote:
> On 17/03/2016 22:02, Håkon Alstadheim wrote:
>> On 03/17/2016 02:03 PM, Bill Kenworthy wrote:
>>> On 17/03/16 20:26, Alan McKinnon wrote:
>>>> On 17/03/2016 08:50, Håkon Alstadheim wrote:
>>>>> I have a server SUPPOSED to be running 24/7, but every once in a while
>>>>> during a prolonged absence the box will go down. The Real Time Clock
>>>>> will drift, and in the rush to get the box up again I let everything
>>>>> boot up automatically and get both wrong time on the main systems, and
>>>>> different times on the various systems.
>>>>>
>>>>> My setup has a main server which does NTP, but with no direct link to
>>>>> the outside. Router&firewall /have/ to be booted booted later (dumb
>>>>> setup, don't ask), after which I can finally get correct time from NTP.
>>>>>
>>>>> NTP initiates "11 minute mode", which makes /etc/adjtime useless as far
>>>>> as I understand. Anybody have a /correct/ way to account for RTC drift
>>>>> on a box running ntpd? Right now I have a ---file in
>>>>> /etc/cron.d/time-bad like so:
>>>>> * * * * * root adjtimex -S 5 >/dev/null 2>&1 </dev/null
>>>>> ---
>>>>>
>>>>> Combined with an old-fashioned setup for hwclock during boot and
>>>>> shutdown. This feels really wrong, and I have no idea what I am doing.
>>>>>
>>>>> TLDR: Anybody have a /correct/ way to account for RTC drift on a box
>>>>> running ntpd?
>>>>>
>>>>>
>>>>

Have you looked at adjtimex ... its in portage


From the man page ...
"For a standalone or intermittently connected machine, where it’s not
ossible to run ntpd, you may use adjtimex instead to correct the sys-tem
clock for systematic drift.

       There are several ways to estimate the drift rate.  If your
computer can be connected to the net, you might run ntpd for at least
several hours and run "adjtimex --print" to learn what values of tick
and freq it settled on.  Alternately, you could estimate values using as
a reference the CMOS clock (see the --compare and --adjust switches),
another host (see --host and --review), or some other source of time
(see --watch and --review).  You could then add a line to rc.local
invoking adjtimex, or configure /etc/init.d/adjtimex or
/etc/default/adjtimex, to set those parameters each time you reboot."

Used it at one time for dialup which approximates your condition.

BillK