Re: initrd -- what exactly is it?
Matt Price said:
> hi there,
>
> can someone help me figure out what exactly initrd is, and why
> kernels use it? I have looked through the docs, and I understand that
> it's thefile used for an initial ramdisk in some cases, but I don't
> understand why it would be used in some cases and not in others. So for
> inst ance, the demudi kernel I just installed seems to demand the use of
> initrd, and I take it GRUB needs an anitrd argument to load the kernel.
> But why don't my own self-compiled kernels require an initrd argument at
> boot (nor have an initrd file anywhere in /boot, as far as I can tell)?
the initrd image usually holds a small basic set of drivers used to
get the system to a basic working state(disk controllers, filesystem
drivers, perhaps raid or LVM as well), so it can mount the root filesystem
and access the 'rest' of the drivers.
I haven't looked into it much but I think it's primarily used so that
you can still use modules in the kernel, having everything built into
the kernel doesn't always work(some drivers may conflict, or may require
certain options to be passed to them to work). If you build your own
kernel for your own hardware, which it seems that you do(I do too) you
probably don't need initrd(I don't use it myself), since you can just build
your drivers directly into the kernel.
nate
Reply to: