Grub loading
error unknown filesystem
grub rescue

type in sudo fdisk -l

ubuntu@ubuntu:~$ sudo mount /dev/sda1/mnt
mount: can't find /dev/sda1/mnt in /etc/fstab or /etc/mtab
ubuntu@ubuntu:~$ sudo mount/dev/sda1/mnt
sudo: mount/dev/sda1/mnt: command not found

sudo mount /dev/sda1 /mnt
ubuntu@ubuntu:~$ sudo mount /dev/sda1 /mnt
mount: wrong fs type, bad option, bad superblock on /dev/sda1,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so
ubuntu@ubuntu:~$ fsck /dev/sda1
fsck from util-linux-ng 2.16
e2fsck 1.41.9 (22-Aug-2009)
fsck.ext2: Permission denied while trying to open /dev/sda1
You must have r/w access to the filesystem or be root