initrd

[James Wilkinson]

Mike Wright wrote:
> I've installed fedora onto everything I could get my hands on, but one 
> of the recurring problems has been building custom initrds for each type 
> of boot device.  Does anybody know if it is possible to build a kernel 
> with enough of the drivers built-in that the initrd is not required or 
> does Fedora require it to boot?

Dan wrote:
> I used to do this, you just need support for your filesystem i.e. ext3
> compiled as part of the kernel instead of loaded as a module. Basically
> setting up the config for a kernel before you compile it. Change the
> filesystem support ext3,jfs,xfs...  to Y instead of M. At least this
> used to work.

"This" presumably being an initrd-less kernel.

The big problem is not the filesystem, it's the device drivers for any
SCSI / SATA adapters, possibly USB drivers, and enough of the RAID and
LVM modules to mount the root filesystem.

You could build a kernel with everything you can think of built-in. This
would make for a big kernel, and the excess modules would continue to
eat memory once the kernel had booted. They couldn't be swapped to disk,
either.

It might be easier just to run "mkinitrd --with= " and specify all the
modules that you can think of. Possibly you could do something like
cd /lib/modules/2.6.17-1.2174_FC5/kernel/drivers
/sbin/mkinitrd --with=$(for i in scsi/* usb/*  ; do echo -n $(basename $i .ko), ; done) /tmp/initrd 2.6.17-1.2174_FC5

Warning -- that's untested (inasmuch as I haven't actually created the
initrd and booted from it. The syntax seems good, though... And I can't
say for certain that's all the modules you'll need, and there's almost
certainly some you don't.)

Hope this helps,

James.

-- 
E-mail:     james@ | [Alan] finally installed his cuckoo clock on the wall.
aprilcottage.co.uk | For some reason this involved falling over in the dark in
                   | the garden, but I haven't dared ask about that yet. I
                   | don't -think- he was trying to catch a cuckoo to put
                   | inside it, but you never know.  -- Telsa Gwynne's Diary