Linux System Configuration and Log Files

Thu, 28 Jul 2022 00:00:00 +0000

This article is part of a series.

Part 1: How to Create Bootable USB? Windows and Linux
Part 2: Introduction to Linux File Systems
Part 3: This Article

Introduction

You will find descriptions of the configuration files you need to set up the different features that make up Linux systems. The two major locations of configuration files are your home directory (where your personal configuration files are kept) and the /etc directory (which holds system-wide configuration files). Most important things for troubleshooting.

Introduction to Linux File Systems

Wed, 27 Jul 2022 00:00:00 +0000

This article is part of a series.

Part 1: How to Create Bootable USB? Windows and Linux
Part 2: This Article
Part 3: Linux System Configuration and Log Files

Linux File System Hierarchy (FHS)

/ (root)
├── /bin → Essential user binaries (ls, cp, mv)
├── /boot → Kernel, initramfs, GRUB
├── /dev → Device files (sda, tty, null)
├── /etc → System configuration files
├── /home → User home directories
├── /lib → Shared libraries for /bin, /sbin
├── /media → Mount points for removable media
├── /mnt → Temporary mount points
├── /opt → Optional/add-on software
├── /proc → Virtual filesystem (kernel info)
├── /root → Root user home directory
├── /run → Runtime variable data
├── /sbin → System binaries (fsck, reboot, ip)
├── /srv → Data for services (web, ftp)
├── /sys → Virtual filesystem (kernel devices)
├── /tmp → Temporary files (cleared on reboot)
├── /usr → User programs (read-only, shareable)
│ ├── /usr/bin → Non-essential binaries
│ ├── /usr/lib → Libraries for /usr/bin
│ ├── /usr/local → Locally compiled software
│ └── /usr/share → Architecture-independent data
└── /var → Variable data (logs, spool, cache)
 ├── /var/log → System logs
 ├── /var/spool → Print/mail queues
 └── /var/cache → Application caches

Common Linux File Systems

ext4 (Fourth Extended): Default for Most Distros

Feature	Details
Max file size	16 TB
Max volume size	1 EB
Journaling	Yes (metadata + optional data)
Backward compatible	ext2, ext3
Defragmentation	Online (`e4defrag`)
Best for	General purpose, SSDs, HDDs

# Create ext4
mkfs.ext4 /dev/sdX1

# Check/repair
fsck.ext4 -f /dev/sdX1

# Tune
tune2fs -l /dev/sdX1

XFS: High Performance, Large Files

Feature	Details
Max file size	8 EB
Max volume size	8 EB
Journaling	Yes (metadata only)
Parallel I/O	Excellent
Online grow	Yes (`xfs_growfs`)
Online shrink	❌ Not supported
Best for	Large storage, media, databases, RHEL default

# Create XFS
mkfs.xfs /dev/sdX1

# Grow (online, mounted)
xfs_growfs /mount/point

# Check
xfs_repair /dev/sdX1

Btrfs: Modern, Feature-Rich

Feature	Details
Max file size	16 EB
Max volume size	16 EB
Copy-on-Write	Yes
Snapshots	Native, instant
Compression	zstd, lzo, zlib
RAID	Native (0,1,10,5,6)
Self-healing	Checksums + redundant copies
Best for	Advanced users, snapshots, Fedora default

# Create Btrfs
mkfs.btrfs /dev/sdX1

# Snapshot (instant)
btrfs subvolume snapshot /source /snapshots/backup-$(date +%F)

# Compress
mount -o compress=zstd /dev/sdX1 /mnt

Other File Systems

FS	Use Case
FAT32	USB drives, cross-platform (max 4GB file)
exFAT	Large USB/SD cards, cross-platform
NTFS	Windows dual-boot (read/write via `ntfs-3g`)
ZFS	Enterprise, data integrity (separate kernel module)
JFS	Legacy, low CPU overhead
ReiserFS	Legacy, small files

Disk & Partition Management

View Disks

lsblk # Tree view
lsblk -f # With filesystem info
fdisk -l # Partition tables
parted -l # GPT/MBR details

Partitioning (fdisk/parted)

# MBR (legacy BIOS)
fdisk /dev/sdX

# GPT (UEFI)
parted /dev/sdX mklabel gpt
parted /dev/sdX mkpart primary ext4 1MiB 100%

Common Partition Schemes

Scheme	Boot Mode	Partitions
MBR	Legacy BIOS	Up to 4 primary (or 3 primary + extended)
GPT	UEFI	128+ partitions, >2TB disks

Typical Linux Layout (GPT/UEFI):

Linux on Madhusudan Upadhyay — ICT Support Executive | Microsoft 365 & Endpoint Management