Installed fedora in order to realize the dual video card installed a bumblebee to realize the dual graphics switch tool. The failure occurred after loading. Automatically enters emergency mode every time you start. Look at the log. The problem occurs because of a node in the disk's DM-2, which is in the root Hang node.
Interesting thing happened to my root hanging node using an encrypted EXT4 file system.
I use Fedora's installation disk to enter recuse mode repair, using auto-hang, unable to fsck, because fsck can not repair the disk is already hanging, and Umount does not work, has been prompted device busy. This method fixes the failure.
Try not to hang on any disk directly fsck, very disappointed that fsck unexpectedly does not recognize the encrypted EXT4 file system.
Later thought the file system is encrypted, found on the Internet the same wrong solution, manual home after the Dm-crypt module, using Cryptsetup to decrypt the file system. Then use LVM Vgscan and Vgchange to mount the LVM volume and then fsck/dev/mapper/everything ... Reboot. All the problems have been fixed.
Summary: The problem occurs after the installation of Bumblebee driver, it is also possible because the firmware version of the SSD is too old bug many caused. The firmware of the SSD has been upgraded to the latest version.
Load the Cyrptsetup module:
sudo modprobe dm-crypt
Decrypt your file system,
sudo cryptsetup luksopen/dev/hda5 crypt1
Get the live CD to recognize (activate) your LVM:
sudo vgscan--mknodes sudo vgchange-ay
Run fsck,
fsck/dev/mapper/
Linux Encrypting File System fsck cannot fix a case