Yes, it is possible to upgrade straight from Fedora 10 to Fedora 12, thereby skipping the dreaded Fedora 11. It wasn’t exactly plain sailing, so here are the steps I went through.

First of all I had to free up all available space on my /boot partition. I cleaned out all old kernels and followed the instructions in ‘not enough space in /boot’ but the Fedora 12 installer apparently requires 26MB of free space in /boot and I had still not freed up quite enough.

I found some extra space by using the following command:

# tune2fs -r 0 /dev/md1

This set the number of reserved filesystem blocks on my /boot partition to zero and gave me around 30MB to play with.

Next for the upgrade itself and for this I used preupgrade (‘yum install preupgrade‘ if you don’t already have preupgrade installed).

# preupgrade-cli "Fedora 12 (Constantine)"

After the F12 packages had been downloaded the system was ready for a reboot.

The upgrade process itself went without any problems, however attempting to boot with Fedora 12 failed with: “Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(0,0)”

I tried various suggested fixes for this but in the end had to build a new initramfs image. To do this I booted into Rescue mode using the Fedora 12 DVD and then after dropping to a shell:

# chroot /mnt/sysimage
# dracut -f /boot/initramfs-$(uname -r).img $(uname -r)


One more reboot and I was finally up and running with Fedora 12.