[systemd-devel] : How to modify systemd so that the NTP function is disabled when systemd is first started?

[www]

hi Michal and Kevin,


We applied systemd to embedded Linux, so we often need to update/flash the whole system.  When we select disable time synchronization function, the embedded system will use the time itself. After we update the system and restart it, we need the time synchronization function is disabled. During the whole startup process, there is no automatic time synchronization, and the previous time is used. Because automatic time synchronization may change its original time. （Because the time of the system itself may be different from that of NTP time.） 


There is a timesyncd.conf file under the system，can the system automatically turn off the time synchronization function by modifying this file? 
In this way, when updating, I can save this file to solve this problem.




thanks,
Byron








At 2020-04-17 19:44:48, "Michał Zegan" <webczat_200 at poczta.onet.pl> wrote:
>I am not quite sure what you mean, but... generally these are symlinks
>in /etc/systemd/system/multi-user.target.wants/ so you could delete them
>manually if your intention is to make the actual os image with this
>disabled from the start...
>
>W dniu 17.04.2020 o 12:10, www pisze:
>> 
>> I mean that this configuration can be preserved, even after I update the
>> system, this function can be saved.
>> 
>> thanks，
>> Byron
>> 
>> 
>> 
>> 
>> At 2020-04-17 18:06:15, "Kevin P. Fleming" <kevin at km6g.us> wrote:
>>>Both of those changes will stop the service from being started, even
>>>when the system is rebooted. You don't need to run these commands
>>>every time, running them one time will change the system configuration
>>>and the service will no longer be started.
>>>
>>>On Fri, Apr 17, 2020 at 2:52 AM www <ouyangxuan10 at 163.com> wrote:
>>>>
>>>> hi Kevin ,
>>>>
>>>> Thank you very much for you help. But how can I save this way of closing time synchronization by command after system boot up? After I update the system, the first time I start it, time synchronization is still enabled by default. It's not appropriate if I close it alone every time. So when I need it start every time, this function is off.
>>>>
>>>>
>>>> thanks,
>>>> Byron
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> At 2020-04-16 18:28:30, "Kevin P. Fleming" <kevin at km6g.us> wrote:
>>>> >There is no need to modify systemd.
>>>> >
>>>> >$ systemctl disable systemd-timesyncd
>>>> >
>>>> >That command will stop the systemd-timesyncd service from being
>>>> >started. It may also be necessary to mask it:
>>>> >
>>>> >$ systemctl mask systemd-timesyncd
>>>> >
>>>> >On Thu, Apr 16, 2020 at 6:22 AM www <ouyangxuan10 at 163.com> wrote:
>>>> >>
>>>> >> Dear all，
>>>> >>
>>>> >> I want to ask a question，How to modify systemd so that the NTP function is disabled when systemd is first started?
>>>> >>
>>>> >>  The default state of systend is to synchronize time from NTP. We can use timedatectl command to disable NTP synchronize time. But if I flash the system, the NTP  synchronize time function will auto enable.  so I want modify the systemd and disable NTP synchronize time in default state.
>>>> >>
>>>> >> thanks,
>>>> >> Byron
>>>> >>
>>>> >>
>>>> >>
>>>> >>
>>>> >> _______________________________________________
>>>> >> systemd-devel mailing list
>>>> >> systemd-devel at lists.freedesktop.org
>>>> >> https://lists.freedesktop.org/mailman/listinfo/systemd-devel
>>>>
>>>>
>>>>
>>>>
>> 
>> 
>> 
>>  
>> 
>> 
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>
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