ubuntu@ubuntu:~$ sudo sudo fdisk /l
fdisk: unable to open /l: No such file or directory
ubuntu@ubuntu:~$ sudo fdisk /l
fdisk: unable to open /l: No such file or directory
ubuntu@ubuntu:~$ sudo fdisk -l

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0001d05b

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *          63    51202047    25600992+   c  W95 FAT32 (LBA)
/dev/sda2        51202048   102402047    25600000   83  Linux
/dev/sda3       102402048   312580095   105089024    5  Extended
/dev/sda5       102404096   306419711   102007808    7  HPFS/NTFS/exFAT
/dev/sda6       306421760   312580095     3079168   82  Linux swap / Solaris
ubuntu@ubuntu:~$ sudo mount /dev/sda2
mount: can't find /dev/sda2 in /etc/fstab or /etc/mtab
ubuntu@ubuntu:~$ sudo mount /dev/sda2 mnt
mount: mount point mnt does not exist
ubuntu@ubuntu:~$ sudo mount /dev/sda1 mnt
mount: mount point mnt does not exist
ubuntu@ubuntu:~$ sudo mount /dev/sda1 /mnt
ubuntu@ubuntu:~$ sudo mount -- bind /dev /mnt/dev
Usage: mount -V                 : print version
       mount -h                 : print this help
       mount                    : list mounted filesystems
       mount -l                 : idem, including volume labels
So far the informational part. Next the mounting.
The command is `mount [-t fstype] something somewhere'.
Details found in /etc/fstab may be omitted.
       mount -a [-t|-O] ...     : mount all stuff from /etc/fstab
       mount device             : mount device at the known place
       mount directory          : mount known device here
       mount -t type dev dir    : ordinary mount command
Note that one does not really mount a device, one mounts
a filesystem (of the given type) found on the device.
One can also mount an already visible directory tree elsewhere:
       mount --bind olddir newdir
or move a subtree:
       mount --move olddir newdir
One can change the type of mount containing the directory dir:
       mount --make-shared dir
       mount --make-slave dir
       mount --make-private dir
       mount --make-unbindable dir
One can change the type of all the mounts in a mount subtree
containing the directory dir:
       mount --make-rshared dir
       mount --make-rslave dir
       mount --make-rprivate dir
       mount --make-runbindable dir
A device can be given by name, say /dev/hda1 or /dev/cdrom,
or by label, using  -L label  or by uuid, using  -U uuid .
Other options: [-nfFrsvw] [-o options] [-p passwdfd].
For many more details, say  man 8 mount .
ubuntu@ubuntu:~$ sudo mount --bind /proc /mnt/proc
mount: mount point /mnt/proc does not exist
ubuntu@ubuntu:~$ sudo mount --bind /proc/mnt/proc
mount: can't find /proc/mnt/proc in /etc/fstab or /etc/mtab
ubuntu@ubuntu:~$ sudo mount --bind /proc /mnt/proc
mount: mount point /mnt/proc does not exist
ubuntu@ubuntu:~$ sudo mount /dev/sda2 mnt
mount: mount point mnt does not exist
ubuntu@ubuntu:~$ sudo mount /dev/sda2 /mnt
ubuntu@ubuntu:~$ sudo mount --bind /proc /mnt/proc
ubuntu@ubuntu:~$ sudo mount --bind /sys /mnt/sys
ubuntu@ubuntu:~$ sudo chroot /mnt
root@ubuntu:/# grub-install /dev/sda
/usr/sbin/grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?).
root@ubuntu:/# mount /dev/sda2 /boot
mount: special device /dev/sda2 does not exist
root@ubuntu:/# grub-install /dev/sda2
/usr/sbin/grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?).
root@ubuntu:/#