Folks that use restic - how does it handle laptop backups?
That is - handling laptop going to sleep during backup, laptop being on only for shorter periods of time, etc.?
Because I had issues with backup tooling which wouldn't resume if it got interrupted and expected for the machine to always run at certain hour of the day. I had examples where laptops wouldn't backup for months because they were only on for a short 30-60min bursts at the time and the backup tools couldn't handle piece-meal resume.
How does restic handle that?
I invoke backups from a systemd timer. If the schedule is missed (due to sleep, power off etc.) it runs it at the next earliest opportunity.
How does it handle restart after the machine wakes up again?
When the machine wakes up, systemd checks the timer's schedule and when it last ran. If one or more runs were missed due to the sleep, it's executed immediately.
On Windows and macOS machines too? How does that work?
https://restic.readthedocs.io/en/stable/faq.html
It will resume from where it got interrupted. The only exception is the initial backup where it doesn't have a snapshot yet.
/etc/anacrontab can solve your use case.