Re: How to read the RTC value?

I want to read the RTC to compare it to the system clock as with
timedatectl. Use cases for this are checking if syncing to the RTC
actually worked or identifying a bug in case the RTC malfunctions. I
don't see how this is so hard to understand. It is just one string to
print. The first thing I would implement when creating the RTC sections
reading and printing the current RTC value.

Am 09.08.24 um 20:25 schrieb Bill Unruh:
>
>
> William G. Unruh __| Canadian Institute for|____ Tel: +1(604)822-3273
> Physics&Astronomy _|___ Advanced Research _|____ Fax: +1(604)822-5324
> UBC, Vancouver,BC _|_ Program in Cosmology |____ [email protected]
> Canada V6T 1Z1 ____|____ and Gravity ______|_ theory.physics.ubc.ca/
>
> On Fri, 9 Aug 2024, Jan Claußen wrote:
>
>> [CAUTION: Non-UBC Email]While chronyd is running with the rtcfile
>> directive, timedatectl shows
>>
>> $ timedatectl
>>                Local time: Fri 2024-08-09 14:12:01 UTC
>>            Universal time: Fri 2024-08-09 14:12:01 UTC
>>                  RTC time: n/a
>>                 Time zone: Universal (UTC, +0000)
>> System clock synchronized: yes
>>               NTP service: active
>>           RTC in local TZ: no
>>
>> When using chronyc's rtcdata command, you get
>>
>> RTC ref time (GMT) : Sat May 30 07:25:56 2015
>> Number of samples  : 10
>> Number of runs     : 5
>> Sample span period :  549
>> RTC is fast by     :    -1.632736 seconds
>> RTC gains time at  :  -107.623 ppm
>> where
>>
>> RTC ref time (GMT)
>> This is the RTC reading the last time its error was measured.
>>
>> so this is not the current RTC value either. How to read it out then
>> without having to stop chronyd?
>
> I am not sure what you mean. You have all the data you need to figure
> out what
> the time is. You know what its time read, you know how slow/fast it
> is, You
> even know how fast it gains or loses time
> Why are you reading the rtc anyway. It is not terribly accurate. And when
> chrony is running, it keeps the time of rtc open not allowing anything
> else to
> read it. You run the system clock to get accurate time. rtc is ONLY
> useful for
> giving the clock a starting time when chrony is started. It is not
> useful as a
> clock unless you are happy with times to nearest second.
>
>>
>>