Partitioning the Hard Disk

                                              Partitioning the Hard Disk

                 As described in the previous section, a disk must be physically formatted (low-level format), partitioned, and logically formatted (high-level format) before it can store data. The partitioning phase creates physical divisions of the disk that can be used to segment the disk and allow for two or more operating systems or the creation of multiple file systems.

Partitioning the hard disk allows you to:

• Divide the disk into logical "sub-drives" that can be addressed separately with a drive letter assigned to each, such as C:,D:, and E:
• Create separate areas on the disk for multiple operating systems, such as storing Windows and Linux on the same hard disk, each in its own partition.
• Separate program files from data files on separate disk partitions to facilitate faster and easier data backups. 

           Partitioning a hard disk can improve the disk's efficiency. For example, windows assigns                      disk clusters (logical collections of sectors) that are sized in proportion to partition size. Bigger            clusters may sound like a good thing, but just the opposite is true. Large disk drives or bigger              partitions result in bigger clusters, which unfortunately result in small unused spaces on the                 disk. By reducing the size of the disk or more smaller partitions, the result is reduced clusters                sizes.                          

                   If you wish to have only one partition on your disk, that's perfectly all right. However,                  you should know that on some systems, if you wish to use the entire  disk, you will have                      to create smaller partitions. For example, on DOS, Windows 3x, or an early release of                         Windows 95, partition sizes must be smaller than 2GB, which means that a disk larger than 2               GB  must be divided into two or more partitions if you wish to us the entire disk. Windows 98             and Windows 2000 allow you to create partitions of up to 4TB (terabytes).

                A hard disk can be divided into two types of partitions:

• Primary partitions: the primary partition contains the operating system and is usually the one from which the  PC is booted. A hard disk can be divided into a maximum of four primary partitions, but on most operating systems, only one primary partition may be active at a time.

• Extended Partitions: this type of partition can be divided into as may as 23 logical partitions, each of which can be assigned its own drive identity. Extended petitions can be used for any purpose.