История изменений

       DefaultTimeoutStartSec=, DefaultTimeoutStopSec=, DefaultRestartSec=
           Configures the default timeouts for starting and stopping of units, as well as the default time to sleep between
           automatic restarts of units, as configured per-unit in TimeoutStartSec=, TimeoutStopSec= and RestartSec= (for
           services, see systemd.service(5) for details on the per-unit settings). For non-service units,
           DefaultTimeoutStartSec= sets the default TimeoutSec= value.

       DefaultTimeoutStartSec=, DefaultTimeoutStopSec=, DefaultRestartSec=
           Configures the default timeouts for starting and stopping of units, as well as the default time to sleep between
           automatic restarts of units, as configured per-unit in TimeoutStartSec=, TimeoutStopSec= and RestartSec= (for
           services, see systemd.service(5) for details on the per-unit settings). For non-service units,
           DefaultTimeoutStartSec= sets the default TimeoutSec= value.
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Как насчет этого? В /etc/systemd/system.conf DefaultTimeoutStopSec=10, например.