I use an Odroid HC4 (two SATA 3 slots) powered by a Shelly smart plug. My backup script powers the plug with a HTTP call. Waits for the server to be online by r

I use an Odroid HC4 (two SATA 3 slots) powered by a Shelly smart plug. My backup script powers the plug with a HTTP call. Waits for the server to be online by repeated ssh attempts. Unlocks the backup disk by asking me the LUKS password. Starts the backup. Sshs to the server to shut it down. Polls the plug over HTTP until the power meter shows a less than one Watt consumption for a while. Eventually powers off the plug, HTTP again. The backup procedure includes a remote encrypted mirror. Power consumed between backups: zero plus the smart plug.