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F16: grub2 fails to install

The upgrade failed, and getting to / proved to be difficult. I apparently ran into this bug:
https://bugzilla.redhat.com/show_bug.cgi?id=771524
Amazing a bug that basic is still around. Basically, the new boot-loader, grub2, ran into trouble (could not install), and it couldn't manage to leave behind a working version of grub.conf for the old grub.

I would like to emphasize that I created significantly more than the amount of free space requested by preupgrade, so we have at least two Fedora 16 bugs here.

I tried (on my MacBook Pro) burning an F16-Live CD-ROM to use as a rescue disk, but it would not boot in my Linux-machine's CD-ROM drive. That's too bad because it is wonderfully small: only half an hour to download and one CD-ROM!

I found an old F12 disk lying around that did boot, so I booted into its shell. I had to press ``SKIP'' at the last step to get a shell because something failed hard when it did the mounting, requiring a hard reset of the machine.

I could mount /dev/sda1 and look around the /boot directory just fine, but nothing I tried would mount /dev/sda2 (because it had a new LVM name that I had no immediate way of knowing). So much for the saved kernel files. Fortunately, the new /boot/grub2 directory appeared to be fully set up and reasonably easy to decipher: The vmlinuz $\ldots$ root= option in /boot/grub2/grub.cfg told me the new name of my main file system, so I was able to cobble together a working /boot/grub/grub.conf that looked like this:

  title Fedora F16
	root (hd0,0)
	kernel /vmlinuz-3.2.7-1.fc16.x86_64 ro root=/dev/mapper/vg_hostname-lv_root
	initrd /initramfs-3.2.7-1.fc16.x86_64.img
where hostname is the host name (run hostname in a shell to find yours). Since the installation of the grub2 bootloader had failed, grub was still doing the booting, and the system came up.

I noticed, by the way, that /dev/mapper/vg_hostname-lv_root is a symlink to ../dm-2 -- I hope it is now ok to mount /dev/dm-2 directly. That would be a huge improvement in my opinion. I have long missed the old /dev/sda2 type names for disk partitions ever since LVM came out.

Since I don't need anything fancy, I hope to simply keep grub and not fight through the grub2 installation headbutts. I'm worried that my 200 MB /boot partition is not up to the task, since there is discussion on the Web about some large files in grub2. That 200 MB boot partition causes me trouble every time I upgrade. I firmly resolve to do a fresh install for F17 on a new disk with at least a 500 MB boot partition (or whatever is recommended). It's hard to think about reserving on the order of a gigabyte for a freaking kernel, but now they're putting exotic and gigantic ``upgrade kernels'' in /boot, along with who-knows-what-else in grub2.


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``My Computers'', by Julius O. Smith III, Web document.
Copyright © 2014-03-25 by Julius O. Smith III
Center for Computer Research in Music and Acoustics (CCRMA),   Stanford University
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