Place to store files that won't be deleted on restart, reboot, or upgrade AND that won't be backed up

I would like to find a safe place where I can store files on HA (running on a pi5) that won’t be deleted when HA is estarted, rebooted (or upgraded) and that won’t be backed up by the backup software (since they may be large and I don’t need them backed up).

If I store files in /data or even /homeassistant (I think) then the files will survive restarts, reboots and even upgrades (I think) BUT they will be backed up.

If I store files in /tmp they won’t be backed up but they also won’t survive a reboot.

Any thoughts on a safe persistent directory that won’t be backed up?

Would network storage work?