[wplug] bootdiskless upgrade

[James O'Kane]

I'm not sure about you, but I so rarely use my floppy drives that they 
tend to not work when I need them. I also seem to have a batch of CDR 
disks that some of my cdrom drives can't boot from, so that leaves few 
standard options for doing an upgrade. (My systems are Red Hat.)

I'm in the middle of an upgrade on a machine right now that I didn't use 
any removable media to do. Here are some of the highlevel steps. 

These assume you have a working Red Hat system now, and can figure out how 
to fix things if they go wrong. If you break something, you keep both 
parts.

1. Make a directory to hold the boot stuff from the installer. I called 
mine /boot/rh9/

2. mount the bootdisk.img
       mount -o loop bootdisk.img /mnt/floppy/

3. copy all of the files from the mounted image.
   cp -av /mnt/floppy/* /boot/rh9/

4. edit /boot/grub/grub.conf, add an entry like this:
title RH9.0 upgrade
        root (hd0,0)
        kernel /boot/rh9/vmlinuz
        initrd /boot/rh9/initrd.img

5. reboot, and select that boot option.

6. I have a local nfs copy of shrike that I was able to access. http or 
ftp access might work, or if you cdrom can be access, but booted from, 
that might work as well.

7. Do the upgrade.

As I mentioned, this is a highlevel overview. In my machine's case, the 
network and scsi drivers were not part of bootdisk.img, so I had to modify 
/boot/rh9/initrd.img, which is a bit of an adventure in itself. When I get 
time, I'll document that process. Until then, here is my modified version: 
http://www.wplug.org/~jo2y/modified-rh9-initrd.img put that into 
/boot/rh9/initrd.img

I think it should also be possible to do a completely remote install
because of the way X works, but I'm still working on that part. It
requires a bit more poking into the internals of anaconda.


-james