Re: [RFC PATCH] Move actually mounting the root filesystem into its own series of hooks.

[Warren Togami <wtogami-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Hi Victor,

I didn't test this patch yet, but I need this kind of structure in order 
to implement different kinds of netboot.

root=dhcp is a kernel cmdline given by the bootloader (syslinux, grub, 
pxelinux, etc.) which directs the initrd during runtime to bring up eth0 
and do DHCP.  It then mounts the rootfs depending on options given by 
the DHCP server.  Fedora 10 mkinitrd implements the following two types 
of mounts with root=dhcp.

         option root-path "172.31.100.254:/path/to/target_root";
         option root-path "nbd:172.31.100.254:2000:squashfs:ro";

An existing RFC specifies syntax for iscsi that could be implemented as 
well.  (Although iscsi is problematic because some types require 
authentication.)  Arbitrary types of root=dhcp rootfs mounts can be 
implemented with hooks made possible with your patch.

Generation
==========
∘ read mode from dracut.conf i.e. MODE=network
∘ if network
	‣ install network modules
	‣ install tools (mount.nfs, nbd, etc.)
	‣ install squashfs.ko
	‣ install custom udev rules to handle network

Boot (contents of udev rule)
============================
∘ if root=dhcp (or later hard coded network)
	‣ ifup eth0
	‣ dhclient
	‣ parse root-path
	‣ if nbd
		• modprobe nbd
		• nbd-client with parameters
		• (mount rootfs)
	‣ if nfs
		• (mount rootfs)

Warren Togami
wtogami-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
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