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CoreOS: Boot on Bare Metal with PXE

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51–58 of 58 posts

Re: CoreOS: Boot on Bare Metal with PXE

#52
post #11

For anyone who does not know what PXE (pixie) boot is, it is an environment to boot computers using a network interface independently of data storage devices (like hard disks) or installed operating systems. [1] In the BIOS, rather than booting from CD, or Hard disk, you would select Network. A very simplified explanation is that the PXE enabled network card (almost all modern network cards support PXE, desktop and s…

It is possible to PXE boot a full blown OS, not just OS installer, Live CD or CoreOS. The product usually used to do this is: http://support.citrix.com/proddocs/topic/technologies/pvs-pr... It is just a nice GUI that ties into PXE and TFTP and just streams an image from a disk file. On a 1Gb network I have booted over 300 physical machines in under 2 minutes simultaneously. For those curious, unfortunately PVS is pac…

[deleted]

Re: CoreOS: Boot on Bare Metal with PXE

#53

For anyone who does not know what PXE (pixie) boot is, it is an environment to boot computers using a network interface independently of data storage devices (like hard disks) or installed operating systems. [1] In the BIOS, rather than booting from CD, or Hard disk, you would select Network. A very simplified explanation is that the PXE enabled network card (almost all modern network cards support PXE, desktop and s…

Can bios detect wireless network or do i need to have Ethernet cable on?

Re: CoreOS: Boot on Bare Metal with PXE

#54
post #30

Earlier quoted context omitted.

> I think stateless immutable servers that boot from the network and run from RAM are going to be a great base layer to build on. Heh, we were doing this 20-25 years ago. It's funny sometimes how I.T. seems to circle back around.

>> stateless immutable servers [emphasis added] >Heh, we were doing this 20-25 years ago. It's possible, but I'd be surprised (unless you mean X servers in the crazy X-windows server-is-really-what-any-sane-person-would-call-a-client sense). Doing this kind of thing is pretty new for servers. Even massive HPC clusters tend to boot from persistent disk.

>Doing this kind of thing is pretty new for servers. Even massive HPC clusters tend to boot from persistent disk.

Not really, no. Servers all over the IT world have been using PXE and tftpboot for decades - in fact it was a very common method of booting a server even in the 80's. I know of quite a few Rail/Transportation companies whose track-side computers are booted over the network using these techniques, and there are about 250,000 of those things just in Europe alone ..

What's new is that another generation are discovering this technique.

Re: CoreOS: Boot on Bare Metal with PXE

#55
post #2

Since I asked for this in the original CoreOS thread, let me be the first to say thanks. I think stateless immutable servers that boot from the network and run from RAM are going to be a great base layer to build on. BTW, if people haven't tried PXE booting before, it's pretty easy with dnsmasq. You can basically read the sample config file and uncomment a few lines. I recommend experimenting with PXE in Vagrant or o…

What are the upsides/downsides of this? It's such a paradigm shift, I'm having a hard time thinking of any advantages.

It's based on the concept of immutable servers http://martinfowler.com/bliki/ImmutableServer.html which helps eliminate errors due to drift. Containers also have lower overhead than VMs.

Re: CoreOS: Boot on Bare Metal with PXE

#56

For anyone who does not know what PXE (pixie) boot is, it is an environment to boot computers using a network interface independently of data storage devices (like hard disks) or installed operating systems. [1] In the BIOS, rather than booting from CD, or Hard disk, you would select Network. A very simplified explanation is that the PXE enabled network card (almost all modern network cards support PXE, desktop and s…

Can bios detect wireless network or do i need to have Ethernet cable on?

There might be some motherboards with built-in WiFi chips that support PXE with configurable access point and security settings. Maybe try a Duck Duck Go search for wifi PXE.

There's no way for the BIOS to know your WPA key automatically, of course, and in general, you'll need wired Ethernet for PXE.

Re: CoreOS: Boot on Bare Metal with PXE

#57
post #29

Earlier quoted context omitted.

"Back in the day" (pre-PXE), we had rooms full of machines -- without hard drives -- that booted completely across the network and mounted all of their filesystems via NFS. https://en.wikipedia.org/wiki/Diskless_node Over the last few years, I've wondered why server vendors don't ship servers with type of flash-based storage (or similar) -- perhaps 4-8 GB -- that's large enough to hold an installation of (for example…

I've been looking at a mSATA SSD and a low profile pcie card for our Ceph cluster to free up the OS/journal drive slots for more 4tb spinning disks.

If you want an SSD on PCIe, any reason why you are not looking at SSDs built into PCIe cards? E.g. OCZ Vector or RevoDrive PCIe cards, but there's several other alternatives too.

Re: CoreOS: Boot on Bare Metal with PXE

#58
post #48
post #9

Earlier quoted context omitted.

We commonly reboot entire clusters at once (around 10,000 servers in larger clusters -- each running a full Linux OS) over PXE without a problem. We have a configuration management machine that creates an image, then we push that down to a small cluster of TFTP servers that serve it out. The strain on NFS (we keep parts of the OS in RAM, and load other parts on demand over NFS) after we kexec from the PXE kernel into…

Since you mention kexec and TFTP+NFS, are you currently using Perceus? Or is there another system out there with that combo?

We're using a modified Perceus tied into cfengine.
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