Broken grub configuration installed by the F9 anaconda

[Sam Varshavchik]

The following happened when I upgraded one of my servers from F8 to F9. The 
machine in question uses softraid for all partitions, and the swap partition 
itself.

The machine in question is a headless router, no X no gnome, and I have a 
manual entry in /etc/fstab that lets me manually mount a DVD. Anaconda 
issued a minor complaint about not being able to mount that specific 
partition, so all partitions may not be available, etc… Previous upgrades 
reported the same warning, which is generally harmless, and I can continue. 
Although I do not believe this was what caused the following issue, I'll 
just mention it for completeness' sake. The same warning came up when 
upgrading to F8, with no ill effects.

Anyway, the upgrade went along its merry way. To avoid wasting any time, I 
upgraded in text mode. It's a little bit faster. Anaconda finished its 
business, and ejected the DVD. No errors reported.

When I reboot, rather than the lovely grub boot menu, I immediately get 
thrown into Grub's famous "WTF do you wanna do now?" command line prompt. 
Splendid. After booting the DVD into rescue mode, the following state of 
affairs presented itself:

Everything seemed to have been installed normally. No problems mounting my 
existing softraid partitions. /dev/md1 was mounted on /mnt/sysimage, 
/dev/md0 on /mnt/sysimage/boot. This is correct, and grub.conf looked 
perfectly kosher.

Chrooting to /mnt/sysimage, and running "/sbin/grub-install /dev/sda" 
produced a rather loud complaint from the script about being unable to map 
the boot devices for /dev/md0 and /dev/md1. That, apparently is the problem. 
It's twofold: grub-install can't figure out what the drives are. Anaconda 
must've ran grub-install, ignored the error, and continued, business as 
usual.

Outside of the chroot jail, the 'mount' command lists all the partitions. 
Once I'm chrooted into /mnt/sysimage, the 'mount' command is silent. It 
turns out that the mount command reads /etc/mtab. Outside of the chroot 
jail, /etc/mtab is a symlink to /proc/mounts. Inside the chroot jail, 
/etc/mtab is an empty file, and mount reports nothing. This, apparently, 
breaks grub-install.

After replacing /etc/mtab with a symlink to /proc/mount, inside the chroot 
jail, /sbin/grub-install was happy, and I was able to reboot into F9. 
Afterwards, I had to manually remove the /etc/mtab symlink, as it was 
confusing other things.

I have another machine with Fedora installed on softraid, so I'll be doing 
this again, within the next week or so. 

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