Systemd lead developer Lennart Poettering has been working on adding the ability to let systemd boot directly into a disk image downloaded via HTTP within the initial RAM disk (initrd) during the Linux boot process.

Poettering is building off other recent systemd additions to allow downloading the root disk image itself via HTTP and attaching it to a loopback device and making it mountable. Ultimately the effort will allow pointing the UEFI to a single URL where it can then load the Unified Kernel Image (UKI) from and in turn picking up the root file-system and booting it up.

The current use-case sought after by Poettering is to help in testing and making it easier for his physical device testing for quickly and easily booting new root file-system images over the network via HTTP whenever the system boots.

This work-in-progress [1]pull request has the preliminary bits for allowing booting from the root file-system acquired via HTTP. Lennart is already looking at extending it to support NVMe-over-TCP and other features in the future.

Those wanting to learn more can read Lennart's comments via [2]Mastodon .



[1] https://github.com/systemd/systemd/pull/36314

[2] https://mastodon.social/@pid_eins/113979730693247159