(no title)
zorlack | 3 months ago
God help you if you actually want to install an operating system.
PXE is such a vital capability for working with on-prem servers. But it's ten different things which all have to play nicely together. Every time I build a PXE system I feel like I'm reinventing the universe in my tiny subnet.
legooolas|3 months ago
hardwaresofton|3 months ago
I just want to start the computer, and have it download an immutable OS image from somewhere I decide (and supply a checksum for, etc). I don't want to set up TFTP or any of this other stuff. It feels like I should be able to just specify an IP (let's say) a checksum (maybe supply that information to the NIC directly somehow), and be off to the races after a reboot.
convolvatron|3 months ago
this allows you intermediate the boot process without coordinating with the administrative owner of the DHCP server, and is actually less janky than PXE
webdevver|3 months ago
"but muh competitive advantage??"
its literally a for loop that reads sectors from disk/network into memory and jumps to the start address.
if a local build of the (vendor provided source code) firmware doesn't match the checksum of the build thats flashed on the actual mobo, you get sent to a cobalt mine.
toast0|3 months ago
UEFI gives you nicer video modes, but not a text mode after boot services.
UEFI has an extension for booting images from the network, but afaik, it's impossible to use, and there's no reasonable way to boot from a disk image; working UEFI network boot has to pull pieces out of the filesytem and present them seperately; as opposed to MEMDISK which makes the image available as a BIOS disk and the image is labeled so that one the OS is loaded, the image can be used without BIOS hooks. If this is possible on UEFI generally, it isn't widely distributed knowledge. Something that will work on any UEFI system that makes it to iPXE, subject to changes to the OS in the image (which is reasonable... MEMDISK needs changes too, unless the OS runs all disk I/O through BIOS APIs)
pjc50|3 months ago
generalizations|3 months ago
zorlack|3 months ago
Some NICs support http. Some NICs support tftp. Some NICs have enough memory for a big iPXE, other NICs don't. Some BMC systems make next-boot-to-lan easy, but not all.
We almost always use iPXE in order to normalize our pxe environment before OS kickstart. There's a lot to it and quite a lot of little things that can go wrong. Oh, and every bit of it becomes critical infra.
kasabali|3 months ago
happyPersonR|3 months ago