List Create Delete and Modify Physical Storage Partitions

In this guide, we'll explore how to effectively manage disk partitions on Linux systems. Using a practical example, imagine you have a 2TB SSD to be split for dual-booting Windows and Ubuntu. Since Windows requires NTFS and Ubuntu uses EXT4, you must divide the SSD into partitions—1TB for Windows and 1TB for Ubuntu. This process is known as partitioning, ensuring each operating system functions independently.

Inspecting Partitions with lsblk

The lsblk command is an essential tool in Linux for listing block devices and their partitions. Running lsblk displays all disks and partitions on your system:

jeremy@kodekloud:~$ lsblk
NAME                  MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda                   8:0    0    45G  0 disk 
├─sda1                8:1    0     1M  0 part /boot
├─sda2                8:2    0     2G  0 part 
├─sda3                8:3    0    43G  0 part 
└─ubuntu--vg-ubuntu--lv 252:0  0 21.5G  0 lvm  /
sr0                  11:0    1 1024M  0 rom

In this output, the disk sda comprises three partitions (sda1, sda2, sda3). Note that Logical Volume Manager (LVM) entries are handled separately. On physical machines, you commonly see disk names like sda1, sda2, etc., while virtual environments may use different naming conventions. For example, a sample layout might be:

sda
  ├─sda1
  └─sda2
sdb
  ├─sdb1
  ├─sdb2
  └─sdb3
sdc
  └─sdc1

Here, the disk identifier (e.g., sda) and the partition number indicate the order and location of partitions. In Linux, every partition is treated as a file in the /dev directory, as shown below:

jeremy@kodekloud:~$ ls /dev/sda1
/dev/sda1

jeremy@kodekloud:~$ ls /dev/sda
/dev/sda

Viewing Detailed Partition Information with fdisk

The fdisk utility offers a detailed view of disk partitions. To display the partition table for /dev/sda, use:

jeremy@kodekloud:~$ sudo fdisk --list /dev/sda
[sudo] password for jeremy: 
Disk /dev/sda: 45 GiB, 48318382808 bytes, 94371840 sectors
Disk model: VBOX HARDDISK
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: F2775F4C-AE12-41CE-B808-027E4304B615

Device         Start      End Sectors Size Type
/dev/sda1      2048       4095   2048   1M BIOS boot
/dev/sda2      4096    419839  419304   2G Linux filesystem
/dev/sda3   4198400  9436791 90171392  43G Linux filesystem

Partitioning Using cfdisk

For users who prefer a more interactive graphical interface, cfdisk is an excellent tool for creating and modifying partitions. Suppose you've added a second storage device and want to partition /dev/sdb. Launch cfdisk with:

sudo cfdisk /dev/sdb

In the cfdisk interface, you'll see how data is stored as a series of 0s and 1s, with the partition table clearly marking start and end points.

Modern systems generally prefer GPT (GUID Partition Table) as it offers enhanced reliability, supports more primary partitions, and supports larger partition sizes compared to older MBR (DOS) systems.

Example: Partitioning a 10 GiB Drive

Imagine you have a 10 GiB drive that needs to be partitioned into an 8 GiB partition for an operating system and a 2 GiB partition for swap. Follow these steps in the cfdisk interface:

1. Navigate to the free space and press the New button. Adjust the partition size to "8G" for the first partition.
2. Use the remaining free space to create a second partition of 2 GiB.
3. If needed, modify partition sizes later using the Resize option. For instance, you can shrink the first partition to "4G" to free up space for an additional partition.

Below is an example of the cfdisk interface:

Disk: /dev/sdb
Size: 10 GiB, 10737418240 bytes, 20971520 sectors
Label: gpt, identifier: B0255EEB-AB12-4FAC-B630-B71E5276803D

Device           Start       End         Sectors    Size Type
/dev/sdb1        2048       16779263    167771216   8G  Linux filesystem
>> /dev/sdb2     16779264    20969471    419208      2G  Linux filesystem

Partition UUID: D1496BAD-498E-419D-98D7-0DF0096F2A5F
Partition type: Linux filesystem (OFC63DAF-8483-4772-8E79-3D69D8477DE4)

[ Delete ] [ Resize ] [ Quit ] [ Type ] [ Help ] [ Write ] [ Dump ]

After sorting, the partition layout might display as follows:

Disk: /dev/sdb
Size: 10 GiB, 10737418240 bytes, 20971520 sectors
Label: gpt, identifier: B0255EEB-AB12-4FAC-B630-B71E5276B03D

Device         Start      End      Sectors  Size Type
/dev/sdb1      2048     8390655   8388608  4G Linux filesystem
>>/dev/sdb2   8390656   16779263   8388608  4G Linux filesystem
/dev/sdb3   16779264   20969471   4190208  2G Linux filesystem

Partition UUID: EED5DAE2-BE25-42C5-A0F5-09FFCD4DFBA3
Partition type: Linux filesystem (OFC63DAF-8483-4772-8E79-3D69D8477DE4)

[ Delete ] [ Resize ] [ Quit ] [ Type ] [ Help ] [ Write ] [ Dump ]

If you wish to change a partition’s type (for example, to designate the 2G partition as Linux swap), select the partition, press the Type button, and then choose "Linux swap" from the available options. Similarly, you can change a partition to the EFI system type if you're setting up a boot partition.

Committing Your Changes in cfdisk

Remember that cfdisk only plans the changes until you commit them. Here’s how to proceed:

• Review all changes and use Quit to undo any unintended modifications.
• Once you are satisfied, press the Write button. Confirm your changes by typing "Yes" when prompted.
• Finally, exit cfdisk by selecting Quit and verify the new partition layout using the lsblk command.

Summary

This guide has walked you through the process of listing, creating, deleting, and modifying physical storage partitions using tools like lsblk, fdisk, and cfdisk. By understanding these fundamental partitioning techniques, you can efficiently manage disk resources and optimize your Linux system installations.

For further reading and advanced partition management strategies, explore our related articles and documentation.

Happy partitioning!