Linux Admin Skills Checklist: What to Learn and Why It Matters
Hi there! I'm Dinesh, a passionate Cloud and DevOps enthusiast. I love to dive into the latest new technologies and sharing my journey through blog.
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Hi there! I'm Dinesh, a passionate Cloud and DevOps enthusiast. I love to dive into the latest new technologies and sharing my journey through blog.
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To install RHEL 9.5 (Red Hat Enterprise Linux) in VMware Workstation or VMware Player on your laptop, follow these step-by-step instructions: ✅ Prerequisites VMware Workstation/Player installed on your laptop. RHEL 9.5 ISO file – Download from Red...
1. Difference between Docker and Kubernetes Docker → Builds and runs containers.Kubernetes → Orchestrates containers across multiple nodes. Key points: Docker = container runtime. Kubernetes = container orchestration tool. Kubernetes provides auto...
In this session, we learn how to monitor a Kubernetes cluster using Prometheus and Grafana.This is not just theory — there is a GitHub repository containing all installation commands and demo steps.The repo will also be enhanced later with advanced K...
1. What is a ConfigMap in Kubernetes? A ConfigMap is used to store non-sensitive configuration data that your application needs — such as: Database port Connection type Any general configuration values In normal applications (non-Kubernetes), de...
Kubernetes normally supports built-in resources like: Deployment Service Pod ConfigMap Secret Ingress These are called native resources. Sometimes companies (Istio, ArgoCD, Prometheus Operator, Kyverno, etc.) want to add new features that Kub...
1. Why Kubernetes Services Are Needed When a Pod is created in Kubernetes, it receives a dynamic IP address.If the Pod dies and restarts, its IP changes.So other Pods (like checkout → payments) cannot rely on Pod IP because it changes, creating issue...
As a Linux Administrator, you need a broad and deep skill set that covers system management, security, networking, automation, and troubleshooting. Here’s a structured guide to what you should learn, categorized by level of expertise:
1. Linux Basics
Linux distributions (Ubuntu, CentOS, RHEL, Debian, etc.)
Filesystem hierarchy (/etc, /var, /home, etc.)
Basic commands: ls, cd, cp, mv, rm, cat, grep, find, etc.
File permissions and ownership: chmod, chown, umask
Text editors: vi, nano
2. User and Group Management
adduser, useradd, groupadd, passwd
/etc/passwd, /etc/shadow, /etc/group
3. Package Management
Debian-based: apt, dpkg
RedHat-based: yum, dnf, rpm
4. Process and Resource Monitoring
top, htop, ps, kill, nice
df, du, free, uptime, vmstat, iostat
5. Systemd & Boot Process
systemctl (starting/stopping services)
Understanding unit files and logs (journalctl)
6. Networking
IP configuration: ip, ifconfig, nmcli
Network troubleshooting: ping, traceroute, netstat, ss, tcpdump, nmap
Hostname resolution: /etc/hosts, resolv.conf, dig, nslookup
7. Disk Management
Partitioning: fdisk, parted, lsblk
Filesystems: ext4, xfs, btrfs
Mounting and unmounting: mount, umount, /etc/fstab
LVM: pvcreate, vgcreate, lvcreate
8. Backup and Restore
Tools: rsync, tar, scp, dd, cron jobs for automation
Snapshots (LVM or filesystem level)
Disaster recovery planning
9. Cron Jobs and Scheduling
crontab, at, anacron
Log rotation (logrotate)
10. Security
SSH configuration: /etc/ssh/sshd_config
Firewall: iptables, firewalld, ufw
SELinux or AppArmor basics
Sudoers file: /etc/sudoers
Fail2Ban, auditd
11. Scripting & Automation
Bash scripting (loops, conditionals, functions)
Basic Python (optional but useful)
Task automation with scripts and cron
12. Configuration Management & Orchestration
Ansible (must-know for modern sysadmins)
Puppet, Chef, SaltStack (less popular now, but still relevant)
Infrastructure as Code (IaC): Terraform (if working in cloud)
13. Logging & Monitoring
journalctl, syslog, /var/log
Tools: Nagios, Zabbix, Prometheus + Grafana, ELK Stack (Elasticsearch, Logstash, Kibana)
14. Virtualization & Containers
KVM, QEMU, VirtualBox
Docker: containers, images, volumes, networks
Podman (RedHat alternative to Docker)
Kubernetes (for container orchestration)
15. Cloud & DevOps Skills
Basics of AWS, Azure, or GCP
Using CLI tools to manage cloud infrastructure
CI/CD tools: Jenkins, GitLab CI, GitHub Actions
16. Kernel & Performance Tuning
Kernel modules: lsmod, modprobe
sysctl tuning (/etc/sysctl.conf)
Analyzing performance: perf, strace, lsof
LDAP and Active Directory integration
Mail servers (Postfix, Sendmail)
Web servers (Apache, Nginx)
Database basics (MySQL, PostgreSQL, MariaDB)
RAID and storage systems (hardware/software)
Bash one-liners and regex
Books:
The Linux Command Line by William Shotts
Linux Administration Handbook by Nemeth et al.
Online Platforms:
Linux Academy / A Cloud Guru
Udemy (look for Linux Admin or RHCSA/RHCE courses)
YouTube (free tutorials)
Certifications (Optional but valuable):
RHCSA / RHCE (Red Hat Certified)
CompTIA Linux+
LFCS / LFCE (Linux Foundation)