Aditya Khade’s Post

Linux looks simple… until you can’t find your own file. 🔹 Linux File System (The Most Important Concept) If you don’t understand this, Linux will always feel confusing. 🧠 What is the Linux File System? Linux doesn’t use drives like C:, D: ❌ 👉 Everything starts from a single root: / Think of it like a tree 🌳 All files and folders branch out from this root. 🔹 Key Directories You MUST Know 📁 /home → Your personal files 📁 /etc → Configuration files (very critical) 📁 /var → Logs & application data 📁 /tmp → Temporary files 📁 /bin → Essential commands 👉 These are used daily in real servers. 🔹 Try This (Hands-on) pwd ls cd / ls cd /home 👉 You just navigated the Linux file system 🎯 🔹 Real-World Scenario Your application is failing ❌ Where do you check logs? 👉 /var/log If you don’t know this, you’ll be stuck while others fix the issue in minutes. ⚠️ Beginner Mistake Running commands without knowing your location: rm -rf * 👉 This can delete everything in your current directory 😬 ✅ Always check first: pwd 🔹 Why This Matters in DevOps Debug production issues Navigate servers quickly Understand where configs & logs live 👉 This is day 1 skill for any DevOps engineer. #Linux #DevOps #AWS #CloudComputing #LearnLinux #DevOpsJourney #LinuxForBeginners

🔧 When a Simple Install Turns Into a Kernel-Level Lesson Today I just wanted to install VirtualBox so I could spin up a Linux machine for practicing and working on some DevOps stuff. I thought it would take a few minutes… but it turned into a small troubleshooting journey. At first, VirtualBox wouldn’t start and kept throwing the rc=-1908 error. After digging a bit, I realized I was running kernel 6.17, and the required module (vboxdrv) wasn’t being built properly. Even reinstalling didn’t help because DKMS still failed to build the module on that kernel. The workaround was booting into a more stable kernel (6.14) so the modules could finally build. I thought that would solve everything, but there was one more blocker: Secure Boot. It was preventing the module from loading and kept returning a “Key was rejected” error. After disabling Secure Boot and loading the modules, VirtualBox finally started working. What I expected to be a simple installation ended up being a good reminder: sometimes issues come from different layers of the system, and the only way forward is to debug them step by step. #DevOps #Linux #Troubleshooting #VirtualBox #Kernel #DKMS #LearningJourney

🚀 Day 11: Linux Internals for DevOps Engineers 👉 Process Monitoring & Advanced Debugging When a system slows down… It’s not the system. It’s usually a process causing the issue. Today I explored how to identify and debug problematic processes in Linux. 📌 What I learned: 🔹 Every process has CPU and memory usage 🔹 Commands like `ps` and `top` help identify issues 🔹 `kill` can stop problematic processes 🔹 Tools like `lsof` and `strace` help in deep debugging 💡 Real Scenario: Server CPU suddenly hits 100%. What do you do? 👉 Run `top` 👉 Identify the process 👉 Investigate it 👉 Take action (restart/kill) This is how real engineers debug production systems. 🧠 Question for you: What is a zombie process, and why can it be a problem? 👇 Drop your answer! 🎯 Learning Goal: To debug system issues by analyzing processes instead of guessing. 📅 Day 12 Tomorrow: Disk Management & Storage (Deep dive) Let’s keep going deeper 🚀 #DevOps #Linux #Debugging #SRE #CloudComputing #SoftwareEngineering #TechLearning #LearningInPublic #ITCareers #EngineeringMindset #CareerGrowth

🚀 Linux Storage & Permissions — Visual Guide I’ve put together a structured visual breakdown of core Linux system concepts that are critical in real-world environments: 🔹 RAID 1 (mdadm disk mirroring) 🔹 File system creation & mounting 🔹 Advanced permissions using ACL (getfacl / setfacl) 🔹 LVM architecture (PV → VG → LV) 🔹 NFS vs NBD (file vs block-level sharing) This is not just theory — the focus is on: • How these components connect • How they are used in production • Practical command flows and real use cases Designed as a clean, minimal, developer-focused PDF: ✔ Visual-first explanations ✔ Command-driven learning ✔ Structured for quick understanding If you're working in DevOps, Linux administration, or backend systems, these fundamentals are essential for building reliable and scalable infrastructure. #Linux #DevOps #SystemAdministration #Storage #LVM #RAID #NFS #Permissions #Backend #CloudComputing

:::writing{variant=“social_post” id=“71645”} 📒 Linux Commands Every DevOps Engineer Should Know Mastering Linux is a must for anyone in DevOps 🔧 Here are some powerful commands I revisited: 📁 Navigation & Basics • pwd, cd, ls -al 📄 File Operations • cat, nano, vim, head, tail 🔍 Search & Filtering • grep, find, awk, sed 🔐 Permissions • chmod, chown 📊 Monitoring • top, htop, df -h, free -h 🌐 Networking & Processes • curl, wget, ps aux, kill ⚠️ Important lesson: One wrong command (like rm -rf) can cause serious damage — always double-check! Consistency and caution are key when working in production environments. #Linux #DevOps #SystemAdmin #Cloud #TechSkills

Day 07 of #90DaysOfDevOps 🚀 Linux File System Hierarchy: Know Where Everything Lives Today I stopped treating Linux as a black box. Time to think like an operator. Every DevOps engineer should know where to look first: → `/etc` — configuration files (nginx, ssh, hosts) → `/var/log` — first stop during incidents → `/tmp` — temporary files → `/opt` — third-party tools (Jenkins, Grafana) → `/home` / `/root` — user environments and permissions What I practiced today: ✅ Mapped core Linux directories with real-world use cases ✅ Diagnosed a failed service using `systemctl status` + `journalctl` ✅ Identified CPU-heavy processes with `ps aux --sort=-%cpu` ✅ Resolved permission issues using `chmod +x` ✅ Located service logs with `journalctl -u <service>` 💡 Most useful takeaway: A service failing after reboot isn't always a crash issue — sometimes it was never enabled to start. Verified with `systemctl is-enabled`. 🔑 Mindset Shift: In production, speed comes from knowing where to check, what to run, and what signal matters first. #90DaysOfDevOps #DevOpsKaJosh #TrainWithShubham #Linux #DevOps

🚀 Linux Command Spotlight: touch One of the most useful Linux commands in daily operations is touch. 👉 touch is used to create empty files or update the timestamp of existing files. 💡 Why it matters in DevOps & System Administration: When working on Linux servers, scripts, configuration files, logs, or application setups, creating files quickly is a common task. 🛠 Real-time Example: touch file.txt Creates an empty file named file.txt. touch app.conf script.sh notes.txt Creates multiple files at the same time. touch /opt/app/config.yaml Creates a file in a specific path. touch existingfile.txt Updates the modified timestamp of an existing file. touch -t 202604191200 sample.txt Creates or updates a file with a specific date and time. touch .env Creates a hidden file. ✅ Common Use Cases: • Creating script files • Preparing configuration files • Creating log files • Updating timestamps for automation tasks • Generating hidden environment files • Creating multiple files quickly A simple command that plays an important role in Linux file handling and server operations. #Linux #DevOps #SystemAdministration #CloudComputing #AWS #Infrastructure #TechSkills #Automation #ITOperations #LinuxCommands

An application failed just because of a wrong file path… Something very small — but exactly the kind of issue that happens in real production environments. 🚀 Learning of my DevOps Journey (Linux Fundamentals): I went deeper into how Linux actually works at system level: ✔️ Explored Linux filesystem structure (/etc, /var, /home) ✔️ Practiced file operations (cp, mv, rm, mkdir, touch) ✔️ Understood absolute & relative paths ✔️ Worked with permissions and file access ✔️ Learned log analysis using grep 💻 Along with this, I practiced a wide range of Linux commands: Process & system monitoring: ps, top, uptime, free Networking tools: netstat, ping, nslookup, dig File & search tools: find, grep, locate, ls Disk & system info: df -h, du, uname, lscpu Package management: apt-get, apt-cache File viewing: cat, less, head, tail 🚨 Then I simulated a real-world issue: ❌ Application unable to locate its configuration file 🔍 Here’s how I debugged it: • Checked file existence using ls • Searched system using find • Analyzed logs using grep ✅ Root cause: Incorrect file path ✔️ Fixed by correcting configuration path 💡 Key Learning: In Linux, even a small misconfiguration (like a wrong path or permission) can break an entire application. The real skill is knowing where to look and how to debug efficiently. 📂 Full documentation: https://lnkd.in/dQDcq-f7 #DevOps #Linux #AWS #CloudComputing #LearningInPublic #Troubleshooting

🚀 Day 12: Linux Internals for DevOps Engineers (Advanced) 👉 Disk Issues in Production (Not as simple as you think) Most people think: ❌ Disk full → delete files → done But real production issues are more complex. Today I explored how engineers actually debug disk-related failures. 📌 What I learned: 🔹 `df -h` shows disk usage 🔹 `du -sh` helps trace large directories 🔹 Sometimes deleted files still occupy space (hidden usage) 🔹 Log rotation is critical to prevent repeated failures 💡 Real Scenario: Disk shows 100% usage… But you can’t find large files. Why? 👉 Because deleted files are still held by running processes. Solution: ✔ Use `lsof | grep deleted` ✔ Restart the process This is something most beginners don’t know. 🧠 Question for you: Have you ever faced a situation where disk was full but you couldn’t find the files causing it? 👇 Would love to know your experience! 🎯 Learning Goal: To debug storage issues deeply and prevent recurring failures. 📅 Day 13 Tomorrow: Networking Basics (IP, Ports, DNS) Let’s keep going deeper 🚀 #DevOps #Linux #SRE #Storage #CloudComputing #SoftwareEngineering #TechLearning #LearningInPublic #ITCareers #EngineeringMindset #CareerGrowth #ProductionIssues

🔧 From Jenkins Failures to Production Hero — A DevOps Linux War Story Last week, a routine deployment turned into a firefight. Jenkins jobs started failing, Nginx returned 502s, and disk space was critically low. The culprit? A mix of full /var, zombie processes, and a memory leak. Here’s what saved the day — real Linux commands every DevOps engineer should have in their back pocket: 🚨 Disk Space Alert df -h → du -sh /* → docker system prune -a --volumes 🔥 High CPU / I/O Wait top → ps -eo pid,comm,%cpu → iostat -xz 1 🧟 Zombie Processes ps aux | awk '$8~/Z/' → kill -9 <PPID> 🔐 SSH / Permission Issues ssh -vvv → chmod 700 ~/.ssh → sudo grep pubkey /var/log/auth.log 📦 Systemd Failing After Reboot systemctl enable docker → journalctl -u docker -n 200 👉 One option: Save this post — it’s your Linux triage cheat sheet. 💬 CTA: What’s your most-used Linux debug command in production? Drop it below 👇 #DevOps #Linux #SRE #ProductionSupport #SysAdmin