From d3a6a3a47dc7d5c25e403167f40ab04e75009203 Mon Sep 17 00:00:00 2001 From: Harsh-02W Date: Sat, 24 Jan 2026 16:34:58 +0530 Subject: [PATCH 1/4] Update my-plan.md with 90-day goals and commitment Expanded on learning goals and commitment for DevOps journey. --- 2026/day-01/my-plan.md | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 2026/day-01/my-plan.md diff --git a/2026/day-01/my-plan.md b/2026/day-01/my-plan.md new file mode 100644 index 000000000..b42b879d3 --- /dev/null +++ b/2026/day-01/my-plan.md @@ -0,0 +1,33 @@ +**My 90 days DevOps and cloud learning plan ** + +- **Current level:** + - I understand the basic the basic idea of DevOps (collaboration b/w devs and ops, automations, and I know that as DevOps it is my job to bring efficiency. + +- **My understanding:** + - As I attend TWS today's live session "DevOps is a mindset and a set of practices that focus on automations, reliability, and time efficiency in software delivery. + +- **Why I am learning DevOps:** + - So heres why I choose DevOps as the skill path the reason is when I got my first internship as web developer in 2023 I got interacted with the IT culturethen it won't take me so long to identify the most interesting and dependable jod in the whole office which is DevOps but life has its own way to treat your ambition and then as I was familier with IT culture I gave interview for a QA role and get selected I work one whole year at this position and by doing this job it brings me more closerto DevOps practices, then in 2025 August I started watching TWS one shot videos and finally when I have have a budget I immediately brought this amazing course. + - the simple reason why I choose DevOps as career path is, it was the only thing which excite me the most at very first time (and I am a huge beliver in love at first sight). I want to be the engineer who keeps system running, scalable, and sane. + +- **Where I want to reach in 90 days:** + - By the end of the 90 days, I want to move from theory to hands-on confidence. + - **MY 3 clear goals:** + - Start earning in huge amount. + - Travel around the world by achiving the peak on remote role. + - Get settle in Singapore/Europe/Japan with my family and give a high level education to my lil bro and excelent environment to my Mom & Dad. + +- **Time Comitment and consistency plan:** + - Week Days: 1.5 - 2 hours. + - Weekends: 5 - 6 hours. + - Total: 16 - 18 hours a week. +- **How I will stay consistent:** + - By maintaining the discipline rather than just being motivated. + - Be patient while learning. + - And as I said DevOps makes me excited I will never get bored. + - Focus hands-on practice, not just watch videos. + +- **Final Comitment:** + - This 90 days plan is not abou t perfection. + - It is about showing-up daily, and building fundamentals the right way. + - System over shortcuts. From 5676c1145b02166a2b8ea07982e2525c3ffd1a4a Mon Sep 17 00:00:00 2001 From: Harsh Warude Date: Sun, 25 Jan 2026 17:01:32 +0530 Subject: [PATCH 2/4] added linux-architecture-notes.md --- 2026/day-02/linux-architecture-notes.md | 0 1 file changed, 0 insertions(+), 0 deletions(-) create mode 100644 2026/day-02/linux-architecture-notes.md diff --git a/2026/day-02/linux-architecture-notes.md b/2026/day-02/linux-architecture-notes.md new file mode 100644 index 000000000..e69de29bb From 1fefa29d985f7c0cc993938f85f807e6d215e94b Mon Sep 17 00:00:00 2001 From: Harsh Warude Date: Sun, 25 Jan 2026 17:12:12 +0530 Subject: [PATCH 3/4] added my today's learnings --- 2026/day-02/.linux-architecture-notes.md.swp | Bin 0 -> 12288 bytes 2026/day-02/linux-architecture-notes.md | 235 +++++++++++++++++++ 2 files changed, 235 insertions(+) create mode 100644 2026/day-02/.linux-architecture-notes.md.swp diff --git a/2026/day-02/.linux-architecture-notes.md.swp b/2026/day-02/.linux-architecture-notes.md.swp new file mode 100644 index 0000000000000000000000000000000000000000..4aea5753861a7ecd46f2ddb0b2e92e43455f3c99 GIT binary patch literal 12288 zcmeI%K}*9h7{>8T&!XtX{<0 z!`SF+9m|pQ&%*iTxOM*N&xPtjTeni~K1oxjqC8HrJ2mm9dgErxsd<@Z>`P0R#|0009ILKmY**5J2Fc2z&vX;61hg literal 0 HcmV?d00001 diff --git a/2026/day-02/linux-architecture-notes.md b/2026/day-02/linux-architecture-notes.md index e69de29bb..5671d0752 100644 --- a/2026/day-02/linux-architecture-notes.md +++ b/2026/day-02/linux-architecture-notes.md @@ -0,0 +1,235 @@ +Linux Architecture – Core Understanding for DevOps + +Linux is not a tool you memorize. +It is a system you learn to reason about under pressure. + +1. Big Picture: How Linux Actually Works + +Think of Linux as three layers, not one OS blob: + +[ User Applications ] + ↓ +[ User Space (Shell, Services, Tools) ] + ↓ +[ Kernel ] + ↓ +[ Hardware ] + + +Rule of Linux: +πŸ‘‰ Nothing touches hardware except the kernel + +Everything else negotiates. + +2. The Linux Kernel (The Authority) + +The kernel is responsible for control and fairness. + +What the Kernel Manages + +Process scheduling (who gets CPU, when) + +Memory management (RAM, swap) + +File systems (read/write permissions, caching) + +Networking (packets, ports, sockets) + +Device drivers (disk, NIC, keyboard) + +Key Insight + +User programs ask the kernel to do things using system calls. +If the kernel says no, the program cannot proceed. + +This is why permissions, limits, and failures exist. + +3. User Space (Where You Live) + +User space contains: + +Shells (bash, zsh) + +Core utilities (ls, ps, grep) + +Services (nginx, docker) + +Your applications + +Why User Space Is Safe + +Crashes don’t kill the system + +Permissions are enforced + +Isolation enables multi-user systems + +If a service crashes, Linux survives. That’s not accidental. That’s design. + +4. systemd and init (The First Breath) +What Happens at Boot + +Kernel loads into memory + +Kernel starts PID 1 + +PID 1 = systemd + +systemd starts everything else + +Why systemd Matters + +Service lifecycle management + +Automatic restarts + +Dependency control + +Centralized logging + +If systemd dies, the system dies. +That’s why PID 1 is sacred. + +5. Process Creation (How Programs Come Alive) +Process Birth + +fork() β†’ parent process duplicates itself + +exec() β†’ child loads a new program + +Kernel assigns a PID + +Every process: + +Has a parent + +Consumes memory + +Competes for CPU + +Nothing is free. + +6. Process States (You Must Recognize These) +State Meaning +R Running on CPU +S Sleeping (waiting for event) +D Uninterruptible sleep (I/O wait) +T Stopped +Z Zombie (dead, not cleaned up) +DevOps Insight + +Many D processes β†’ disk or network issue + +Many Z processes β†’ bad parent process + +High R β†’ CPU saturation + +This is how incidents start. + +7. systemd in Practice (Real Control) +Core Actions +systemctl status nginx +systemctl start nginx +systemctl stop nginx +systemctl restart nginx +systemctl enable nginx + + +systemd ensures: + +Services start after reboot + +Failed services restart + +Logs are traceable + +8. Logs: Where Truth Lives +systemd Logging +journalctl +journalctl -u nginx +journalctl -xe + + +Logs explain why, not just what failed. + +No logs = blind debugging. + +9. 5 Commands Used Every Day +Command Why It Matters +ps aux See all processes +top / htop Resource monitoring +systemctl Service control +journalctl Logs +kill Stop broken processes + +These are not optional skills. + +10. Interactive Checks (Do These) + +Try this on your system: + +ps -p 1 + + +β†’ Confirm systemd is PID 1 + +systemctl list-units --type=service + + +β†’ See active services + +top + + +β†’ Observe CPU ownership + +journalctl -b + + +β†’ Read boot logs + +11. Why This Matters for DevOps + +Every DevOps failure eventually becomes: + +A stuck process + +A failed service + +A resource bottleneck + +A mismanaged restart + +Linux knowledge lets you: + +Diagnose instead of guessing + +Act instead of panic + +Fix instead of rebooting blindly + +This is the difference between an operator and an engineer. + +Final Mental Model + +Kernel = judge + +systemd = conductor + +Processes = workers + +Logs = history + +You = debugger + +Master this, and Docker, Kubernetes, and cloud systems stop being mysterious. + +Next logical continuation (no rush): + +Linux β†’ Containers + +systemd β†’ Kubernetes control loops + +Processes β†’ Pods + +Same ideas. Bigger scale. From 7bcedd3dca3ffc0121b6b9a2dde8a83262a64403 Mon Sep 17 00:00:00 2001 From: Harsh-02W Date: Sun, 25 Jan 2026 17:13:40 +0530 Subject: [PATCH 4/4] Format title in markdown for emphasis --- 2026/day-02/linux-architecture-notes.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/2026/day-02/linux-architecture-notes.md b/2026/day-02/linux-architecture-notes.md index 5671d0752..ba3df57d8 100644 --- a/2026/day-02/linux-architecture-notes.md +++ b/2026/day-02/linux-architecture-notes.md @@ -1,4 +1,4 @@ -Linux Architecture – Core Understanding for DevOps +**Linux Architecture – Core Understanding for DevOps** Linux is not a tool you memorize. It is a system you learn to reason about under pressure.