Partition :

To divide the hard disk space into different drives is known as partition.

Types of partition :

By default in any OS there are three types of partition :-

• Primary partition which is used to install OS.


• Extended partition - after three primary partition, the remaining free space is known as extended partition.


• Logical partition which is used to store user data.

Partitioning tools :

Pre-installation tool [at the time of installation] => Disk Druid

Post-installation tools [in Windows disk management] => fdisk and parted [ these commands are used to create, delete or check the list of partition after installation of OS]

Naming convention of hardware devices :

Sata Hard Disk - /dev/sda

IDE Hard Disk - /dev/hda

DVD-RW - /dev/sr0 

Pen Drive or USB - /dev/sdb

[root@localhost~]#fdisk -l
This command is used to check the list of partition with the size.

[root@localhost~]#fdisk /dev/sda
This command is used to create a partition.

Command action :
   a - toggle a bootable flag
   b - edit bsd disklabel
   c - toggle the dos compatibility flag
   d - delete a partition
   l - list known partition types
   m - print this menu
   n - add a new partition
   o - create a new empty DOS partition table
   p - print the partition table
   q - quit without saving changes
   s - create a new empty Sun disklabel
   t - change a partition's system id
   u - change display/entry units
   v - verify the partition table
   w - write table to disk and exit
   x - extra functionality

[root@localhost~]#parted -l
This command is also used to check the list of partition with the size. [It provide more user-friendly information]

Create a partition using fdisk command :

 
To check the list of partition with the size -
[root@localhost~]#fdisk -l

To create a partition -
[root@localhost~]#fdisk /dev/sda

Command (m for help): n 

First cylinder (3634-3917, default 3634): [Enter] (To avoid giving size of partition in cylinder)

Last cylinder, +cylinders or +size{K,L,M}{3634-3917, default 3917}: +10GB

Command (m for help): p  [lets say we already have 9 partition available so, the new partition will be /dev/sda10]

Command (m for help): w

To update new partition table without restarting the OS -
[root@localhost~]#partprobe /dev/sda  [for CentOS 7 or RHEL 7]
[root@localhost~]#partx -a /dev/sda  [for CentOS 6 or RHEL 6]

Format the partition to create file system -
[root@localhost~]#mkfs.ext4 /dev/sda10  [ext4 is a file system]

To check the partition file system with id number -
[root@localhost~]#blkid /dev/sda10
 

Delete a partition using fdisk command :

To delete a partition -
[root@localhost~]#fdisk /dev/sda

Command (m for help): d
Partition number (1-10): 10
Command (m for help): p
Command (m for help): w

Mounting :

Mounting is a method which is used to access any device (partition, CD-ROM, USB device, network device etc.) with the help of mount point.

Mount point :

A mount point is a directory which is linking with specific device (access point).

To mount a partition : [to activate any device]

Create a directory -
[root@localhost~]#mkdir /dir1

Mount the partition -
[root@localhost~]#mount /dev/sda10 /dir1

To check all the mounted partition list -
[root@localhost~]#mount

To store data in mounted partition -
[root@localhost~]#touch /dir1/file1

To deactivate the partition -
[root@localhost~]#unmount /dir1

Mounting a partition permanently :

[root@localhost~]#vi /etc/fstab
This command is used to mount a partition permanently.

fstab (file system table) - It is used to mount the partition permanently 
with the help of partition name, file system, mount point & default permission.

Example :

[root@localhost~]#vi /etc/fstab
fstab file will be opened, then press i/I/o/O/a/A (any one of them) to go to insert mode. 
Now go to end of the file and type :

/dev/sda10 /dir1 ext4 default 0 0 

Then press wq to save and exit.

To update permanent mounted partition -
[root@localhost~]#mount -a