Setting: A Raspberry Pi 1B+ (Rev 1.2) is operated as restic backup server over a tailnet connection.
The device is configured as nearly read-only to reduce wear on the SD card, i.e. /tmp, /var/tmp and /var/tmp are mounted as tmpfs and swap is deactivated.
File transfers of a few megabytes have always succeeded.
Problem: For file transfers with several gigabytes, the memory usage of the tailscaled process (on the server side) slowly increases; eventually the tailnet connection freezes and the file transfer terminates with IO errors on the restic client side.
The server side Raspberry remains inaccessible even after the restic backup task has stopped.
A quick solution leverages Go environment variables on the server side,