[mythtvnz] Database management

[Stephen Worthington]

On Sun, 25 Jul 2021 11:45:51 +1200, you wrote:


>Hi
>
>'sudo systemctl edit fstrim.timer' created     /etc/systemd/system/fstrim.timer.d/override.conf
>
>The directory: '/fstrim.timer.d'     was created too, as it did not formerly exist.
>
>I copied the contents of:   '/lib/systemd/system/fstrim.timer' into the empty 'override.conf' file and  altered them as below:
>
>[Unit]
>Description=Discard unused blocks once a day
>Documentation=man:fstrim
>ConditionVirtualization=!container
>
>[Timer]
>OnCalendar=daily
>AccuracySec=10m
>Persistent=true
>
>[Install]
>WantedBy=timers.target
>
>
>Let me know if that's all ok.
>
>Thanks
>Paul

No, that is not the right way to do it.  Override files do as the name
implies - any settings in an override file will override the matching
setting in the base file.  So you do not copy the base file, just put
only the settings you are changing into the override file.  So in this
case, the override file should only contain just what I posted.

There are some extra rules for override files to make them work
properly.  Some settings can be used multiple times, so if you use
such a setting in an override file, it will be added to the list of
such settings that will be used.  For such settings, if you want to
change existing settings in an override file, you have to tell systemd
to delete all the existing settings of that name and then add back in
the new ones that you want.  You do that by using a setting name with
an = after it but nothing more on the line - that deletes all existing
settings of that name.  Then after that line in the override file, you
put your new settings.  So in my post, you will see the line
"OnCalendar=", which deletes all the existing OnCalendar settings,
followed by "OnCalendar=daily".  So only "OnCalendar=daily" will be
use.  With what you have done, you have added the "OnCalendar=daily"
setting to the existing "OnCalendar=weekly" setting, and now both will
occur.  Which, fortunately, will not break anything, but is not ideal.