Master Linux Disk Partitioning and Mounting: A Step‑by‑Step Guide

Linux Operations: Disk Partitioning and Mounting Explained

1. Principles of Disk Partitioning

Disk partitioning divides a physical hard‑disk into separate logical sections, each of which can be treated as an independent storage device, allowing better space management and data isolation.

2. Viewing Disk Devices and Partition Information

The lsblk command lists block devices, their sizes, types and mount points.

[root@zyl-server ~]# lsblk
NAME    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda       8:0    0 30G  0 disk 
├─sda1   8:1    0  1G  0 part /boot
└─sda2   8:2    0 29G  0 part 
  ├─centos-root  26G 0 lvm /
  └─centos-swap   3G 0 lvm [SWAP]
sdb       8:16   0 10G  0 disk 
sr0      11:0    0 4.4G 0 rom  /mnt/cdrom

Explanation of the columns:

NAME   : device name
MAJ:MIN: major/minor numbers
RM     : removable (0 = no)
SIZE   : capacity
RO     : read‑only flag (0 = writable)
TYPE   : disk or partition
MOUNTPOINT: where the device is mounted (empty if not mounted)

Use lsblk -f to display filesystem types and UUIDs.

3. Creating a New Partition on a New Disk (e.g., /dev/sdb)

Run fdisk /dev/sdb to enter the interactive fdisk prompt. Press m for help, then n to create a new partition, choose primary ( p ) or extended ( e ), specify the partition number, start and end sectors (or size, e.g., +10G), and finally w to write changes.

4. Formatting the Partition

After creating /dev/sdb1, format it with the desired filesystem, e.g., ext4:

mkfs -t ext4 /dev/sdb1

5. Mounting the Partition

5.1 Temporary Mount

Create a temporary mount point and mount the partition:

mkdir /mnt/temp
mount /dev/sdb1 /mnt/temp

Verify with lsblk that the partition is mounted.

5.2 Permanent Mount

Create a permanent mount point, edit /etc/fstab, and add a line such as: /dev/sdb1 /mnt/data ext4 defaults 0 0 Then run mount -a to apply the changes.

6. Unmounting the Partition

Unmount by device path or mount point:

umount /dev/sdb1
umount /mnt/data

Ensure no processes are using the mount point; otherwise, you will see a “device is busy” error.

7. Deleting a Partition

In the fdisk prompt for /dev/sdb, press d to delete a partition, choose the partition number, then w to write the changes.

fdisk /dev/sdb
# d (delete)
# 1 (partition number)
# w (write and exit)