Re:Netboot.xyz: your favorite operating systems in one place
by latchkey on Monday June 20, 2022 @11:17PM
(#31819450)
That's really cool. Luckily, our datacenters where these machines are all Tier 3, so the full reboot doesn't happen very often. We've only had to shut down a lot of racks once for some power management issues. It was a bit of a struggle, but things eventually booted.
The bigger issue that we faced was that dnsmasq couldn't keep up with all the UDP packets and we had to switch to Kea kind of mid-flight, which was a bit of work since it was a weekend (of course things fail on friday night) and restarting everything to get new leases (and a few with duplicate IPs) was a bit of nail biting. It all sorted itself out though and we haven't had any more issues on that front.
Re:Netboot.xyz: your favorite operating systems in one place
by HeckFeck on Tuesday June 21, 2022 @04:42AM
(#31821736)
That sounds a bit like UDP multicast. One of those tragically under used features of the networking stack. Ripe for abuse were it exposed on the open Internet certainly, but still very cool.
Re:Netboot.xyz: your favorite operating systems in one place
by linsomniac on Tuesday June 21, 2022 @11:14AM
(#31824889)
Yes, it was indeed built on UDP multicast.
Basically: The systems would PXE boot the bootloader (or maybe it was burned locally to the boot ROM or similar, I don't recall). Then firebreather would spray the kernels and associated boot data over multicast to all the machines at once. Any that were lagging behind or missed packets, would catch them the next time around, firebreather would spray the images a few times or something.