[ipxe-devel] iPXE and booting ISOs over the network

[Geert Stappers]

On Fri, Jun 12, 2020 at 07:06:16PM +0200, Christian Nilsson wrote:
> On Fri, 12 Jun 2020 at 16:49, IT1 Stuart Blake Tener, USNR wrote:
> 
> > List members,
> >
> > I have done a number of web searches and am interested in gaining some
> > insights into what choices I have in implementing iPXE to boot ISO files
> > directly (I have read several postings that were 6 to 10 years old in this
> > area but no code was really given just oh I did this, I did that). I had
> > asked in an IRC channel a while ago (they are so useless, people ignoring
> > your question and trying to find a different question you should be asking
> > because that is what they can answer), and got a bunch of discouraging
> > replies. A huge discussion ensued having nothing to do with what I had
> > originally asked, and I abandoned obtaining any help there.
> >
> > I'd like to setup a server (as a virtual machine for portability, but
> > would be fine starting as a physical server to decrease complication) with
> > a singular purpose of providing iPXE/PXE booting services on my home lab
> > network. I'd like to be able to have a directory or that into which I can
> > plop an ISO file and then have some sort of menu generated on the fly that
> > notices all ISOs in that directory and offers a menu that is presented
> > whence someone boots iPXE/PXE via the network. I'd also like to have a
> > sub-menu of permanent ISO choices with descriptions that can be selected
> > from as well. It is my understanding that iPXE/PXE can do this quite
> > easily, but then I was given a ton of reasons on the IRC why it would not
> > work so I gave up in frustration trying to sort "IRC wheat from IRC chaff".
> >
> > My thought is to create a private 192.168.100.0/24 network in this
> > environment I propose, and for the server to have TFTP, DNS, and whatever
> > else is requisite installed there within. I think I'd like to use Debian to
> > do it, but am open to whatever distribution people think will make this
> > most easiest.
> >
> > Thanks in advance and I hope everyone stays safe from looting thugs and
> > healthy from the pandemic.
> >
> >
> > Very Respectfully,
> >
> > Stuart
> >
> In the iPXE forum FAQ you have the "answer" to ISO - it is still a valid
> answer! (the way PCBIOS INT calls work won't be changed, and EFI has
> similar issues in this regards, so there is no reason to think that a 10
> year old answer is invalid)
> https://forum.ipxe.org/showthread.php?tid=5948&pid=19101#pid19101
> See the part about: I'm using memdisk or sanboot to boot an ISO and bootup
> fails
> 
> It boils down to: booting ISO might work if what is on the ISO does not
> start it's own OS (that is keep using the BIOS for all access and iPXE
> stays active)
> But as soon as you have some other driver that takes control of the NIC
> (actually before that but it's an easy way to understand when things happen)
> There is no longer any way to access the disk (ISO) and it usually fails.
> (There is a few exceptions where this does work, but not many)
> So due to the fact that the "boot a ISO over PXE" will fail in most cases,
> it is better to pursue an approach that is known to work.
> 
> Just to be clear, first start with getting the iPXE demo boot to work the
> way you want, people will be happy to help you with that!
> Then feel free to try out booting ISOs, you might be lucky that it works,
> but please remember that those are special cases.
> (it is more likely that you will see isolinux or grub work fine, but when
> Linux kernel boots it will fail to find the live system, since "there won't
> be" any ISO that it can be found from)

In https://discourse.ubuntu.com/t/netbooting-the-live-server-installer/14510
do I read something that I'm now sharing here.  What I understand from it:
* Have a "special" .iso    [0]
* Netboot
* Linux boot parameters for  ramdisk and url=http://server/path/the.iso

The interresting line
 APPEND root=/dev/ram0 ramdisk_size=1500000 ip=dhcp \
 url=http://cdimage.ubuntu.com/ubuntu-server/daily-live/current/focal-live-server-amd64.iso 


I hope it will bring "network booters" and "ISO booters" closer ...

 
> Kind regards
> Christian

Regards
Geert Stappers

Footnote
[0] How special "special" is, is indeed the question
-- 
Silence is hard to parse