You can always press control-c during the boot cycle. That should drop you to shell. Then turn on swap (swapon /swapfile), unmount and check all of your filesystems (umount /drive0; umount /drive1; fsck -fay /; fsck -fay /dev/hda4; fsck -fay /dev/hdc4) and then reboot. You will still get that building databases the first time, but you should be able to go into shell normally then and correct it by hand.