• Multiple Filesystems – When user creates a Hard Disk partition, he needs to format the hard drive it to make it functional. When formatting a hard disk partition user specify the OS what the filesystem user would use that hard disk partition to be formatted in. After user formats that partition. If one wants a different filesystems on their system, he can then make severel hard disk partition.
• Partition Size - On older OS the max size of that particular hard disk partition was limited.
• Multiple Operating Systems - Some OS use filesystems that are not suitable with other OS. If user wants to use more then one operating systems on the same system that are not friendly in this way, user then make more hard disk partitions, one for each OS.
• Wasted disk Space – After storing data on the filesystems, the larger the hard disk partition, the higher the ratio of wasted free space. By creating several partitions of different smaller size, one can reduce the ratio of waste that filesystems may create.

In IBM PC architecture, the hard disk partition table in the hard disk drive’s Master Boot Record that lists in sequence about the particular partitions on the HDD. This HDD partition table is then additional divide into four HDD partition table entries, with every entries equivalent to a HDD partition. These four hard disk partitions are normally known as primary Hard Disk partitions. To rise above this limitation, computer programmer decided to insert a new type of HDD partition which is known as the extended HDD partition. By swap 1 of the 4 primary HDD partitions with 1 extended HDD partition, user can make an extra twenty four logical HDD partitions within the single extended HDD partition.

The HDD partition table is broken up into four primary hard disk drive partitions. The 4th partition, although, has been assigned as an extended hard disk partition. This permits us to create extra logical HDD partitions under one extended HDD partition.

Every HDD also has 1 of its probable four partitions ensign as an active hard disk partition. The active HDD partition is a special assigned to only single HDD partition that the MBR uses to start the system into an OS. As only single HDD partition may be set as the main HDD partition, to install multiple operating systems this can be done by installing a boot loader in the active HDD partition. When the system starts, it will read the Master Boot Record and examine the Hard disk partition that is assigned as active partition. This active partition is the single partition that contains the boot loader. When the OS boots off of this active partition the boot loader will start and allow to select the OS.

Even though hard disk partitions are logically independent, they are connected when they are installed. At the system start up.

On MS installed computers each Hard Disk Drive and each partitions of every hard drive as well as is nominated by a drive letter. The 1 and the main partition on the first Hard Disk Drive is always nominated by C:, and other partition by letters such as D: and E: or the other drives.

There are many ways to know about hard disk partitions on Linux operating system. df command is the easiest, but this only shows those hard drive partitions that are presently mounted. It is mainly suitable to use this command with its -h i.e.,

df -h

fdisk, which is positioned in the /sbin directory,to show the hard disk partitions on the computer, and also can be used to change the partitions of the hard disk drive.

On computer in which any user is allowed to become the root user, such as a Personal computer, the access the root can be done easily by using the su command. Then fdisk command can be used to access the Hard Disk Drive, with the first Hard Disk Drive designated by /dev/hda, the second designated by /dev/hdb. Thus, the mentioned command would access the 1 Hard Disk Drive:

/sbin/fdisk /dev/hda

The hard disk partition table for the selected Hard Drive can then be seen by the letter p and pressing the ENTER key.

Hard disk drive is the main data storage device. Storage device means a media that keep the data for quite long time until unless it will not be deleted or corrupted, in compare with memory, which can be accessed at high speeds but the data is retained only temporarily.

The sizes of partitions can be easily formed on a Hard Disk Drive during the fresh installation of an OS. New hard disk partitions can also be formed after the OS has been installed by deleting existing hard disk partitions to create free space.

An OS can be installed on a single partition, and this can be done with the MS windows. However, dividing a single hard disk drive into multiple partitions offers extra advantages.

(1) A way for a single Hard Disk Drive to contain multiple OS.

(2) The capability to summarize data due to filesystem corruption is bounded to a particular partition, the main use to have more then single partition is that it makes it likely that only that data will be lost which is present on that particular hard disk partition if that partition becomes damaged or get corrupted. Several partitions allow the user to reinstalled the data without affecting the data present on other hard disk partitions.

(3) Several HDD partition avoid runaway processes i.e. execution of program while booting the system.

(5) Make things easier to backing up important data.

(6) Creating partition increase hard disk space effectiveness. Hard disk partitions can be created with different sizes, this is depending on usage of the user which is different for different users.

With Disk Operating System, Operating System/2, and MS Windows, the normal partitioning scheme is to make a 1 active hard disk primary partition, C: where the OS, Windows applications, user files all reside. A number of users, though, prefer to make many hard disk partitions so that the OS can store data separately. Proponents of extra hard drive partitions normally point to the advantage of being able to delete a single hard drive partition while the other data remain un changed or deleted. When used in combination with 3-party hard drive partition management software such as Norton PartitionMagic, Norton Ghost, or any particular data recovery software which comes with system manufacturers, the main use of extra HDD partitions allows the users to easily recover data from viruses and trojan horses or else damaged, get corrupted OS.