GRUB question

[horseriver]

> Of course, an initrd on floppy is kind of silly, because you still need to
> find someplace else to fit the actual kernel - which hasn't fit on a floppy
> for quite some time.
  
  Do  we must  need initrd.img  to boot system ?

> >
> >   Does this /boot/initrd.img file come out when building kernel ?
> >   how to build it?
> 
> Your system should have either 'mkinitrd' or 'dracut' to build the
> initrd image. Some older systems will have 'mkinitramfs'.

  I know how to make a initrd image file , but put what data into it?


Thanks!