"You've already got cloud storage. Add alerting for yourself if the user hasn't backed up within an acceptable period of time." To wit: rsync.net has user-cus

"You've already got cloud storage. Add alerting for yourself if the user hasn't backed up within an acceptable period of time." To wit: rsync.net has user-customizable "idle alerts" (or, inactivity alerts) that you can set at any threshold you like and which will generate any combination of emails, SMS, pushovers or webhooks. "Then, hook up a spinning USB drive to their laptop dock at work or whatever, and enable Time Machine/Windows Backup." ... and although I am certain the OP knows this, just in case, let me point out that your .zfs/snapshot directory contains user-configurable "snapshots" of your entire account that are live, browseable and immutable. So whatever you set up with Time Machine, you can set up in your rsync.net account with ZFS snapshots.[1] [1] By default, 7 daily, but configurable to any combination of days/weeks/months/quarters/years ...