Disk Spacing Commands

ls -lSr    Show files by size, biggest last
df -h      Show free space on mounted filesystems
df -i       Show free inodes on mounted filesystems
fdisk -l  Show disks partitions sizes and types (run as root)

Mounting Devices and File System

you can store your data in different physical storage devices, like floppies, CD-ROMs, and hard disk drives.
Your hard disk or disks are also very likely split up into different partitions with different filesystems.

mount: mount a file system or devices
umount : Unmount file system or devices
Examples:-

Mounting Floppy Drive
$ mount /dev/fd0 /mnt/floppy

Mounting CD-ROM Drive
$ mount /dev/cdrom /mnt/cdromdrive

umount : Unmounting the file system.

Examples:-

Umounting Floppy Drive
umount /mnt/floppy

Umounting CD-Rom Drive
umount /mnt/cdrom

Mounting Windows File system
mount /dev/hda1 /mnt/windows vfat user 0 0

To make set the Windows partition to be mounted every time the system starts, the /etc/fstab entry would be like the following:

mount /dev/hda1 /mnt/windows vfat auto,user 0 0

Mounting SATA Drive

mount -t ntfs /dev/sda1 /mnt/drive_windows

Mounting Windows Xp/Vista/7 file system in Linux

mount /dev/sda5 /mnt/shared32 vfat auto,umask=0 0 0