Urban:
> Hendrik Boom wrote on 16.11.18 19:08:
...
> > (2) What is initramfs good for? Linux used to work just fine without
> > it.
>
> It's only needed if you have to do stuff before running the `real´ init
> process to bring up the system and all services. If, e.g., for some reason
> you decided to place stuff like kernel modules or other essential system
> components not in the root file system and therefore have to perform some
> special action and mounting before being able to bring up user space in
> its final form.
>
> Most, if not all, contemporary Linux based operating systems should be
> able to boot just fine without resorting to any kind of initramfs mechanism,
> provided all the essential bits are located in the root-fs, and the kernel
> has all the drivers necessary to access said root-fs compiled in.

You will have problems doing that when the boot fs is on a partition on
a md-raid partition and probably when the boot fs is somewhere on a lvm
thing. At least you'd have the problem of telling the kernel where the
root fs is that has dynamic device numbers and must be assembled or
something before the rootfs is available.

Booting from a md-raid with v0.90 metadata can be done though, since
theese can be autodetected by the kernel, and the same is valid for
nfs-booting; though the kernel devs. seems to view that as a hack and
points to initrd as the solution.

Regards,
/Karl Hammar

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