nbdkit is our high performance Network Block Device server for serving disk images from unusual sources. One (usual) source for Linux installers is to download an ISO from a website like Get Fedora or debian.org. However that costs the host money and is also a central point of failure, so another way to download Linux installers is over BitTorrent. Many Linux distros offer torrents of their installers including Fedora and Debian. By using these you are helping to redistribute Linux and defraying the cost of hosting these ISOs.
Now I’ve written a BitTorrent plugin for nbdkit so you can download, redistribute and install Linux all at the same time!
$ url=https://torrent.fedoraproject.org/torrents/Fedora-Server-dvd-x86_64-32.torrent $ wget $url $ nbdkit -U - torrent Fedora-Server-*.torrent \ --run 'qemu-system-x86_64 -m 2048 -cdrom $nbd -boot d'
So what’s the serious use for this? It has the interesting property that the more people who are installing your Linux distro, the less bandwidth it uses and the faster it runs! This could be interesting technology for any kind of distributed environment where you have lots of machines accessing the same fixed/read-only filesystem or disk image.
If you want to get started with nbdkit it’s already in all popular Linux distributions, and compiles from source on Linux, FreeBSD and OpenBSD.
Richard WM Jones 