Next time you want to play mp3s and the like it's much better to follow one of the guides (autoplus or RPMFusion repository) at http://www.fedoraforum.org/?view=fedora_setup
here to get the codecs you might need. I find with both smplayer and vlc pretty much any video is playable. Realplayer might well cause problems, and I can't see any advantage in installing it.
Sometimes there is an option to boot to a rescue shell in the grub boot menu. Also, while booting you will often be given a rescue shell or able to access a shell if things are not working correctly. CTRL+ALT+F2 might switch you to a shell.
Changing the order of your drives shouldn't cause problems in modern distributions.
I would recommend booting from your install media and checking out your current install. You can access it by booting a live cd and going to the terminal.
First mount your root partition:
open a terminal and change to root user:
To figure out which drive your install is on try
ie. sda, sdb etc. Your linux partition will be identified in one of your drives. If it is an LVM partition it will be stated as such.
Mount the partition
mount /dev/sdxn /mnt
Or if you have used lvm
mount /dev/mapper/xxx /mnt
You can use the tab key to complete the drive names, ie. /dev/mapper/[tab] will show you a list of your options.
After you have successfully mounted your root directory you can get console access to your system with the following commands:
mount -o bind /dev /mnt/dev
mount -t sysfs /sys /mnt/sys
mount -t proc /proc /mnt/proc
At this point you can make changes to your system as if you were running the system, such as working with yum and checking what happened when your boot failed
# Last 50 lines
tail -n 50 /var/log/messages
and reloading grub:
grub2-mkconfig -o /boot/grub2/grub.cfg
If this causes an error you might have other partitions. You can check your fstab with
to see the partitions that are saved to be mounted on your system. If any of these partitions are referenced by their physical disk ie. /dev/sdxn, this will cause problems when you change the order of your disks. You can use a text editor, like
to fix these values to match your current setup.
If your /boot partition was listed in /etc/fstab you will need to remount it before you can reinstall grub simply by typing
If you do have to reinstall though, just back up your home folder in its entirety. Most of your configuration files are stored in your home directory prefixed with a '.' char. You can see them by opening a terminal and typing 'ls -A'. After reinstall many of your settings will remain if you replace your home folder. This is probably the simplest option. I would recommend just packing it
tar cvf /targetdir/myname.tar /home
to pack your entire home folder into /targetdir/myname.tar. Then to unpack in your new system (use the same username of course), as root
cp /targetdir/myname.tar /
mv /home /homebackup
tar xvf myname.tar
# If all was successful then
rm -r /homebackup #this will delete the backup of your new installs home directory