Disk Management Basics

Disk Management

• Disk Management is an essential aspect of systems administration, involving tasks such as adding storage, partitioning disks, formatting and managing file systems.

• Caution: Handle disk management tasks with care, as modifications can impact your data. Always back up important information before making changes.

Adding Storage

• Physical Disks: Connect a new disk to your server. Verify that the disk is recognized in the BIOS/UEFI and ensure device files are created in the /dev directory.
• Virtual Disks: In virtual environments (VMs or cloud), add a disk using the management tools or dashboards.

Linux Drive Naming

• Linux utilizes a different approach to drive naming compared to Windows.
• Drives and partitions are represented as files located in the /dev directory.
• The naming pattern is typically in the format of sdXY or hdXY, where:
  • X is a letter representing the physical drive (a for the first, b for the second, etc.).
  • Y is a number representing the partition on the drive (1 for the first, 2 for the second, etc.).
  • sd stands for SCSI drives, and it's also used for SATA drives and SAS drives found in modern systems.
  • hd stands for IDE or ATA drives, older drive types rarely used in modern systems.

Verifying Detection

• Use commands like lsblk to check if the system recognizes the newly added disk.

lsblk Command

• Lists all available block devices (disks and partitions).

Creating Partitions

• Partitions divide a disk into separate sections, each with its own file system.
• This helps in organizing data and enhancing security.
• Common examples include:
  • / (root) partition: for essential system startup files
  • swap partition: stores virtual memory
  • /home partition: stores user files
  • /boot partition: contains the boot loader and kernel.

fdisk Command

• A command-line tool for managing disk partitions.
• You can use it to display information about disks and their partitions.

Formatting Partitions

• Use the mkfs command with the desired file system type (-t option) and device or partition name (e.g., /dev/sdX1).
• Example: Creating an ext4 file system:
  • sudo mkfs.ext4 /dev/sdX1

Mounting and Unmounting File Systems

• Mounting makes a file system accessible, while unmounting detaches it.
• Steps for mounting:
  • Create an empty directory as the mount point using mkdir.
  • Mount the partition to the mount point using the mount command.

Automounting

• By default, file systems mounted using the mount command are not automatically mounted at system boot.
• To enable automatic mounting at boot, add an entry to the ** /etc/fstab** (file system table) file.

Checking the File System

• Use fsck to check and repair file systems.
• Run it on unmounted file systems to avoid data corruption.

Logical Volume Management (LVM)

• LVM provides flexible disk management by abstracting physical storage into logical volumes.
• This allows for easier disk space management, volume resizing, and snapshot creation.
• Components:
  • Physical Volume (PV): The actual disk or partition.
  • Volume Group (VG): A collection of PVs.
  • Logical Volume (LV): A virtual partition within a VG.

Checking Disk Usage

• df command reports file system disk space usage.

du Command

• Shows disk usage of files and directories.

This quiz covers the essential aspects of Disk Management, focusing on tasks such as adding storage, partitioning disks, and managing file systems. Learn about physical and virtual disks, and understand the naming conventions used in Linux. Ensure you grasp the importance of managing disk changes carefully.