Skype raised an interesting question: are we missing delivering updates to some users because their particular usage pattern leaves the computer off when updates are scheduled? For example, let’s say updates are 6am, noon, 6pm, midnight for me. Every day I get to work for 8am and close my laptop at 11 for lunch. Every day I leave at 5:30pm.
Put another way: do we run on boot refreshes that were missed?
snapd comes with the snapd.refresh systemd timer by default (can be found in /lib/systemd/system/snapd.refresh.timer) to manage package refreshes.
that timer unit uses the “Persistent” directive (which makes it behave like an anacron job) …
Persistent=
Takes a boolean argument. If true, the time when the service unit was last triggered is stored on
disk. When the timer is activated, the service unit is triggered immediately if it would have been
triggered at least once during the time when the timer was inactive. This is useful to catch up
on missed runs of the service when the machine was off. Note that this setting only has an
effect on timers configured with OnCalendar=.