Putting Your Linux Home Server to Sleep and Waking it on Demand

This article details how the author automated their Ubuntu home server to sleep when idle and wake on demand (e.g., via SSH or Time Machine backups). This involved using an always-on device (like a Raspberry Pi) to act as an ARP and mDNS proxy, along with configuring Wake-on-LAN and a cron job on the server to detect idle states. The author meticulously outlines the configuration, including enabling Wake-on-LAN's unicast mode, creating a cron script, disabling IPv6, and setting up an ARP Stand-in and Avahi service. Challenges encountered, such as unexpected wake-ups and Time Machine backups failing to trigger wake-up, are addressed and solved through port mirroring and service adjustments.