Diskless Booting For the Modern Age

An anonymous reader writes "Ever wonder what happened to PXE? Intel's popular standard for diskless booting hasn't been updated since 1999, and has missed out on such revolutions as wireless Ethernet, cloud computing, and iSCSI. An open source project called Etherboot has been trying to drag PXE into the 21st century. One of their programmers explains how to set up diskless booting for your cloud, using copy-on-write to save space."

Comments

How is it slow?

[OrangeTide]

TFTP over UDP on a LAN, doesn't seem slow at all. It's stupid, but sufficient to bootstrap a small kernel to access the real meat of your OS. 1-10MB TFTP downloads over 100mbit is no big deal. You can't get good 1gbit performance (let alone 10gbit) out of the dumb drivers in a PXE boot ROM, but that's OK.

PXE/DHCP/AoE

[Anonymous Coward]

I did a similar thing a while ago with an Ubuntu desktop image and ATA over Ethernet. Worked nicely. Didn't get round to COW though ...

    http://www.s-mart.net/aoe.txt

Authentication

[Anonymous Coward]

The one thing missing from PXE is authentication: A PXE system will accept any DHCP address and with it any boot server configuration. Without cryptographic boot image authentication, network security is the Achilles' heel of PXE.

Re:Authentication

[Anonymous Coward]

It's still an omission. If you use PXE for remote administration (instead of using it for completely diskless operation), then there is local data which can be compromised by a hostile PXE payload. How hard would it have been to verify a cryptographic signature against a public key stored in the BIOS configuration?

i dont wonder......

[Ruede]

i am using pxe often.

i have setup a few linux install "CDs" for network install, a few live CDs for an emergency OS. LTSP is using it too and a small intel atom box gets its kernel over tftp/pxe... the pxe provides the parameters for the nfsroot mount.
old win2k netinstall for ppl without a RIS uses that system too :)
the tftpd box that provides all that stuff is a small amd geode that is normally my router :)

i often thought about making a sourceforge project out of it.... :)

I haven't been wondering...

[langelgjm]

I still use PXE to boot a diskless MythTV client. For a while I had the machine connected to a wireless router set up in bridge mode, so the machine effectively netbooted wirelessly.

Re:Cloud?

[warrior389]

My grandfather was telling me about how he used to walk inside of an old cray with 5 processors like 50 years ago. What happened to the people who used to know how to program those things efficiently? Apparently multi-core programming isn't so new.

Works pretty well and scales well too

[pdbaby]

We do this at work - we chain-load gPXE using PXE and then use that to iSCSI boot from a Linux SAN which uses LVM COW snapshots. It's pretty good - the etherboot project rocks! We've been doing it for a while but it always gives me a kick when I type something at the commandline which wakes up a machine using IPMI & then boots it off some SAN volume

A few interesting things...

[Junta]

The DHCPv6 netboot standard about to come out recommends http as the protocol of choice where tftp would have been used, but uses URLs so the protocol is selectable.

The iSCSI portion of this is a wider standard, implemented by many firmware configurations out of the box.

Finally, I'm going to plug xCAT as a tool to wrap dhcp, dns, ntp, active directory, gPXE, iSCSI, PXE, bootp/tftp, ipmi, blades, vmware, kvm, xen, LPARs, and more to deploy vmware, windows, linux, and aix systems and do hardware management. It mostly pays off at larger scale, but it is a project that aims to understand how to best utilize those various technologies.