No, just different cron schedules. If I just reboot a machine the job doesn't get triggered, only if I start a machine after the cron schedule should have been triggered. To be fair, if I start two machines in these conditions this will happen too, but such situation is much more manageable than rebooting too machines in a short period of time.
Typo, I meant tolerates. Fixed it.
Not an option either, because if I reboot two machines and the backup starts in both of them it'll cripple my NAS
How does systemd on the 2 machines avoid that? Are they communicating somehow?
No, just different cron schedules. If I just reboot a machine the job doesn't get triggered, only if I start a machine after the cron schedule should have been triggered. To be fair, if I start two machines in these conditions this will happen too, but such situation is much more manageable than rebooting too machines in a short period of time.
"tolerates".