Disk Management in Linux

Disk management in Linux involves the process of handling disk devices, partitioning, formatting, mounting, and managing storage space on a Linux system. It’s essential for maintaining the system’s data integrity and optimizing storage usage. Here’s a comprehensive overview of disk management in Linux:

1. Understanding Disk Devices in Linux

In Linux, storage devices are represented as files in the /dev directory. These files are not actual physical files but represent disk devices. Some common device names are:

  • /dev/sda, /dev/sdb: These represent the first, second, and subsequent hard drives (SATA, SCSI, etc.).
  • /dev/sda1, /dev/sda2: These represent partitions on the first hard drive.
  • /dev/sr0: Represents an optical drive (CD/DVD).
  • /dev/mapper/: Represents logical volumes (in the case of LVM – Logical Volume Manager).

2. Disk Partitioning

Partitioning is the process of dividing a storage device into distinct sections, called partitions, each of which can act as a separate disk. Linux typically uses partitioning tools like fdisk, parted, or gparted (graphical) to create and manage partitions.

Common Partitioning Tools:

  • fdisk (for MBR – Master Boot Record):
    • sudo fdisk /dev/sda: Launch fdisk for the first disk (/dev/sda).
    • Commands: n (new partition), d (delete partition), p (print partition table), w (write changes).
  • parted (for GPT – GUID Partition Table):
    • sudo parted /dev/sda: Launch parted to manage partitions.
    • Commands: mkpart (create a new partition), rm (remove a partition), print (list partitions).
  • gparted (Graphical interface):
    • sudo apt install gparted: Install gparted for graphical partition management.
    • It provides a user-friendly interface for creating, resizing, and deleting partitions.

3. File System Creation

Once a partition is created, it needs to be formatted with a file system (e.g., ext4, xfs, btrfs, etc.) to make it usable.

Common File System Types:

  • ext4: The most commonly used file system for Linux. It supports large volumes and files.
  • xfs: A high-performance journaling file system used for large systems.
  • btrfs: A newer file system with advanced features like snapshots, RAID support, and volume management.
  • ntfs: File system used by Windows (Linux can read/write with additional drivers).
  • vfat/exFAT: Common file systems used for flash drives, compatible with Windows and macOS.

Formatting a Partition:
To format a partition, use the mkfs command:

ext4:
sudo mkfs.ext4 /dev/sda1
xfs:
sudo mkfs.xfs /dev/sda1


4. Mounting and Unmounting Partitions
Mounting is the process of making a partition or disk available for use by attaching it to a directory in the Linux file system. The directory to which it is attached is called the mount point.

lsblk – Lists information about block devices (disks and partitions).


This command provides details about disks, including their size, type, and mount points.
Shows detailed partition tables of all disks.
fdisk -l

 

blkid – Shows block device attributes like filesystem types.


A more advanced partitioning tool, useful for managing partitions on both
MBR (Master Boot Record) and GPT (GUID Partition Table) disk schemes.
parted -l


Partitioning Disks
Partitioning a disk involves dividing it into multiple partitions.The most common tools used
for partitioning in Linux are:
fdisk: For MBR (Master Boot Record) disks.
sudo fdisk /dev/sda

 

This command starts an interactive session where you can create, delete, and modify partitions.

gdisk: For GPT (GUID Partition Table) disks..
sudo gdisk /dev/sda

 

Creating Filesystems
Once a disk or partition is created, you need to format it with a
filesystem. Some common filesystem types
include ext4, XFS, and Btrfs. To create a
filesystem, use the following commands:
sudo mkfs.ext4 /dev/sda1

Example: Create an XFS filesystem:
sudo mkfs.xfs /dev/sda1
mkfs.fat: Used for creating FAT32 filesystems,
often used for USB drives or small partitions.
sudo mkfs.fat -F 32 /dev/sda1

Disk Partition Tools (Graphical)

Ifou prefer using a graphical interface, several tools are available:

  • GParted: A GUI tool for managing partitions. It allows resizing, creating, and deleting partitions with an easy-to-use interface.
  • Disks (gnome-disk-utility): Another simple GUI tool available in many Linux distributions for partitioning and mounting drives.

How to check hdd?
sudo fdisk -l

How to check partition MBR/GPT?
gdisk /dev/sda
lsblk

 

 

How to create partition ?
sudo fdisk /dev/sda
help- m
n
enter
enter
+20G
p- print
w-save
fdisk -l

 

 

How to format partition ?
mkfs.ext4 /dev/sda
lsblk -f -chcek format or not partition

How to mount partiton?
sudo mount /dev/sda /<mount folder>
check – sudo mount
lsblk

How to Manage and Use LVM (Logical Volume Management)

LVM

Physical Volume = pv
Volume Group = vg
Logical Volume = lv

How to View Current LVM Information
pvdisplay


fdisk /dev/sdb

n = create new partition
p = creates primary partition
1 = makes partition the first on the disk


t = change partition type
8e = changes to LVM partition type


p = view partition setup so we can review before writing changes to disk
w = write changes to disk

 

1 – pvcreate /dev/sdb1 <create a LVM physical volume on the partition we just created>

Create volume Group

2 – vgcreate vgpool /dev/sdb1

Create logical volume

3 – lvcreate -L 3G -n lvstuff vgpool

Format and Mount the Logical Volume

4 – mkfs -t ext3 /dev/vgpool/lvstuff

Create a mount point and then mount the volume somewhere you can use it.

5 – mkdir /mnt/stuff
mount -t ext3 /dev/vgpool/lvstuff /mnt/stuff

Resizing a Logical Volume


6 – vgextend vgpool /dev/sdc1

Extend Logical Volume

7 – lvextend -L8G /dev/vgpool/lvstuff

8 – resize2fs /dev/vgpool/lvstuff

 

How To Cheking Linux Ubantu Disk Status ?
lsblk
fdisk -l
df -hT
lsblk -f <Cheking Formating Partition >
mount -av <cheking Mounting>

 

How To Create Linux Ubantu LVM ?
Step#01 fdisk /dev/sdb <Go To HDD >
Step#02 n, p, t, 8e, w <New Partion Create>
Step#03 partprobe /dev/sdb <Karnel Infom For New HDD Partition>
Step#04 pvcreate /dev/sdb1 <Create Pv>
Step#05 vgcreate nextcloud /dev/sdb1 <Create VG>
Step#06 lvcreate -L 500G -n nextcloud nextcloudlv <Create LV>
Step#07 mkfs.ext4 /dev/mapper/nextcloud-nextcloudlv <Formating>
Step#08 mount /dev/mapper/nextcloud-nextcloudlv /var/www/html <Create Mount Point For Use Disk Space>
Step#09 df -hT <For Checking Mount>
Step#10 cat/etc/mtab <Copy Full Path nextcloud-nextcloudlv For Entry Fstab>
Step#11 nano /etc/fstab
Step#11 /dev/mapper/nextcloud-nextcloudlv /var/www/html ext4 errors=remount-ro 0 1 <Paste This Line Fstab Then Save>

 

How To Cheking Linux Ubantu LVM Status ?
pvdisplay
vgdisplay
lvdisplay
lvs
vgs
pvs
lvscan
pvscan
vgscan

 

How To Remove Linux Ubantu LVM ?
lvremove /dev/nextcloud/nextcloudlv

How To Check Partition Style MBR or GPT

fdisk -l /dev/sda

parted /dev/sda print <Checking HDD Information>
parted /dev/sda mklavel msdos <MBR>
parted /dev/sda mklavel gpt <gpt>