[CentOS] How to rebuilt the pxe initramfs

Hello Guys,

i read the official red hat documentation of "How built pxe initramfs",
but it does not work"

the inluded version of initramfs is about 42MB, mine 13MB.

This is again one of more failure of redhat documentation. 
That's why i ask here.

In my despair tried a very hard version:

dracut -v -f -m "nfs network base" --add-drivers "nfsv4
(find /lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/net )
$(find /lib/modules/3.10.0-514.el7.x86_64/kernel/drivers/virtio/) ";
chmod 644 /boot/initramfs-3.10.0-514.el7.x86_64.img

In the past i did it on ubuntu and it works flawless - means in
principal I know what I do.

Thanks for help

Sincerely

Andy

PS: given kernel & initramfs from iso boots..