[Fedora-livecd-list] Live ISO within initrd for PXE Boot?

[Warren Togami]

http://git.fedoraproject.org/git/?p=livecd;a=commit;h=e0f0269d3a8f8f310e7c5fdfb8af45892f419c13
> 
> The way it works is to bundle the complete ISO image inside the initrd.
> The kernel and (bloated) initrd are downloaded using PXE in the normal
> way, and the init script finds and loopback-mounts the ISO image and
> booting continues as normal.

Wow.  I don't mean to offend, but this seems like an incredibly bad way 
of doing this.  Isn't this really slow in the boot up because you must 
wait for the entire ISO to download?  It also requires the client to 
have more than enough RAM to have the entire ISO in memory?  It sounds 
like the entire memory used by the ISO remains unavailable to the booted 
system.

I need something similar to boot read-only OS images over PXE boot for 
LTSP.  Upstream LTSP5 uses nbd to serve a raw squashfs image as a 
network block device, which means only a tiny bit needs to be in the 
initrd and very little memory overhead.  Parts of the read-only image 
are streamed over the network on demand.

I'm waiting on Jeremy to get back regarding a long-term plan for 
supporting mayflower-like things within mkinitrd itself.  NBD support 
was not accepted into mkinitrd because it would rely upon mayflower-like 
functionality to do right.

Warren Togami
wtogami at redhat.com