boot from a large iso file

[NiKiZe]

Loading large isos over network is generally a horrible bad Idea.

Instead Load the kernels properly as they should.
First of small isos will be easier to load because they are small.
But they generally succeed because they are not acutally used by the booted OS since they only contain a kernel and initrd - and the ISO contents is not actually used after kernel is started.

Large ISOs will take long to load, will fill up memory, and contents still won't be available after boot. If you still want to boot large isos over the network you might use iSCSI but it will need support by the booted kernel to load network drivers initialize iSCSI and connect to the target with data from the iBFT ACPI table. This is something that will only work for few of the isos that are available.

Instead of this, clearly explain what you are trying to boot and maybe we can help you on the way, also search the forum, many explanations for different distros have already been given.

One other similar discussion: http://forum.ipxe.org/showthread.php?tid=8017