To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.

[email protected]:~$ sudo -i
[email protected]:~# mount /dev/sda7 /mnt
[email protected]:~# grub-install --root-directory=/mnt/ /dev/sda
Installation finished. No error reported.
This is the contents of the device map /mnt//boot/grub/device.map.
Check if this is correct or not. If any of the lines is incorrect,
fix it and re-run the script `grub-install'.

(fd0)    /dev/fd0
(hd0)    /dev/sda
[email protected]:~#

[email protected]:~# sudo cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
/dev/sda9       /               ext4    errors=remount-ro 0       1
/dev/sda8       none            swap    sw              0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0
[email protected]:~# ls /media
BC9B-2C32  F097-BD83  FC3B-4049  floppy  floppy0
[email protected]:~# ls /mnt 
[email protected]:~# ls /mnt