done tasks of week01

2026/day-01/learning-plan.md

@@ -0,0 +1,2 @@
+in simple understanding devops means complete end to end process desigining and deploying applications.consists of two words dev +ops 
+dev means development in which code ,plan and features are included but in operations (ops) the code si deployed on servers where continous monitoring happens

2026/day-02/linux-architecture-notes.md

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+* process states
+1 running- means the process is currently in execution 
+2 sleep -process waiting for its execution
+3 stopped - proces is paused by user or other 
+4 zombie - hwne process is terminianted but in process table and wiating for exit
+5 dead - when process is completely terminated and nt present in process table
+* 5 commands that i will use daily
+cd - to navigate between dir
+mkdir - create a new dir
+vim - for text editor
+touch - for creating new file
+man - for description
+pwd - to check current working directory
+systemctl - to know logs of system
+

2026/day-03/linux-commands-cheatsheet.md

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+* Basic commands
+cd - to navigate between dir
+mv - to move or rename file
+cp -copy file
+pwd - current directory
+ls - lsit all files
+ls -a - list hidden files
+ls -l - list the permissions of file
+mkdir - make dir
+touch - create file
+whoami - display user name
+cat - edit file
+* adding user or group
+useradd - add user in environment
+useradd -m - add suer in home dir also
+groupadd - add new group
+usermod - to modify the permissions
+chown - change owership
+chgrp - change group ownership
+ssh-keygen = genrate new keys
+su - to with users
+* file permissions
+chmod - change permissions
+* to know about systems
+systemctl - to manage service on linux like start,stop,restart,reload
+
+* network commands
+ipcongig - to check all ip address
+ping - send ICMP requests
+dig - Dns lookups in nslookups

2026/day-04/linux-practice.md

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+Process checks
+ps - snapshot of current process
+top - this provides dynamic view of running system
+pgrep - looks htrough the currently running process and lists the process IDs 
+    pgrep [options] pattern 
+
+Service checks
+systemctl - gives log for system and controls systemd
+systemctl list-units - units are a managed resource this command helps to check the acitve services,sockets,mounts
+
+Log checks 
+journalctl -u ssh - print logs of the specific service
+tail -n - 50 this shows the last 50 entries 
+
+Mini troubleshooting steps

2026/day-05/linux-troubleshooting-runbook.md

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+
+
+## Target Service
+ssh (OpenSSH Server)
+
+## Environment
+- Kernel: Linux 6.14.0-1018-aws (x86_64)
+- OS: Ubuntu 24.04.3 LTS (Noble Numbat)
+- System uptime low, clean boot state
+
+## Filesystem Sanity Check
+Commands:
+- mkdir /tmp/runbook-demo
+- cp /etc/hosts /tmp/runbook-demo/hosts-copy
+
+Observations:
+- Temporary directory created successfully
+- File copy succeeded with normal permissions
+- Filesystem is writable and healthy
+
+## CPU & Memory
+Commands:
+- top- this provide the list fo processes
+- free -h - this display the storage in human readable format
+
+Observations:
+- CPU is 99% idle, load average near zero
+- No high CPU processes observed
+- Memory usage is low with ~510MB available
+- No swap usage or memory pressure
+
+## Disk & IO
+Commands:
+- df -h- This display file system usage in 1000 powers
+- du -sh /var/log
+
+Observations:
+- Root filesystem only 36% utilized
+- /var/log size is ~35MB
+- No disk space or IO concerns
+
+## Network
+Commands:
+- ss -tulpn
+- ping -c 3 localhost
+
+Observations:
+- sshd listening on port 22 (IPv4 and IPv6)
+- Localhost connectivity is healthy
+- No packet loss or latency issues
+
+---
+
+## Logs Reviewed
+Commands:
+- journalctl -u ssh -n 50
+- tail -n 50 /var/log/auth.log
+
+Observations:
+- SSH service starts cleanly after reboot
+- Successful key-based logins observed
+- No authentication errors or service crashes
+- Log entries appear normal and expected
+
+---
+
+## Quick Findings
+- System resources are healthy
+- SSH service is stable and responsive
+- No indicators of CPU, memory, disk, or network issues
+- Logs show normal operational behavior
+
+---
+
+## If This Worsens (Next Steps)
+1. Restart ssh service gracefully using systemctl and monitor logs
+2. Investigate failed login attempts and review firewall or security group rules

2026/day-06/file-io-practice.md

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+root@Asus:/mnt/c/users/# cd documents
+root@Asus:/mnt/c/users/documents# touch name.txt
+root@Asus:/mnt/c/users/documents# cat "hello my name is " > name.txt
+cat: 'hello my name is ': No such file or directory
+root@Asus:/mnt/c/users/documents# man cat
+root@Asus:/mnt/c/users/documents# man touch
+root@Asus:/mnt/c/users/documents# mv name.txt notes.txt
+root@Asus:/mnt/c/users/documents# echo "hello my name si :" > notes.txt
+root@Asus:/mnt/c/users/documents# echo "hi everyone" >> notes.txt
+root@Asus:/mnt/c/users/documents# echo "I am student of batch 10 " >> notes.txt
+root@Asus:/mnt/c/users/documents# cat notes.txt
+hello my name si :
+hi everyone
+I am student of batch 10
+root@Asus:/mnt/c/users/documents# head notes.txt
+hello my name si :
+hi everyone
+I am student of batch 10
+root@Asus:/mnt/c/users/documents# man head
+root@Asus:/mnt/c/users/documents# head -n 2 notes.txt
+hello my name si :
+hi everyone
+root@Asus:/mnt/c/users/documents# tail -n 2 notes.txt
+hi everyone
+I am student of batch 10
+root@Asus:/mnt/c/users/documents# tee "hello" >notes.txt
+hello
+my name is
+i am student of batch 10
+^C
+root@Asus:/mnt/c/users/documents# cat notes.txt
+hello
+my name is
+i am student of batch 10
+root@Asus:/mnt/c/users/documents# tee hello
+hello
+hello
+i am
+i am

2026/day-07/README.md

@@ -116,7 +116,7 @@ Write at least 4 commands in order.
 - Then check: What do the logs say?
 - Finally check: Is it enabled to start on boot?
 
-**Commands to explore:** `systemctl status myapp`, `systemctl is-enabled myapp`, `journalctl -u myapp -n 50`
+**Commands to explore:** `systemctl status myapp`, ` myapp`, `journalctl -u myapp -n 50`systemctl is-enabled
 
 **Resource:** Review Day 04 (Process and Services practice)
 

2026/day-07/day-07-linux-fs-and-scenarios.md

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+### Part 1: Linux File System Hierarchy
+- '/' (root) - This contains the boot files of system 
+- '/home' - this conatisn file configurations and users
+- `/root' - This is subdirectory inside '/' which has full user access
+- 'etc' - this contains editable configurations files
+- '/var/log' - This contains the log of system
+- '/tmp' - these are created for short term uses and they got deleted when system reboots
+
+### Part 2: Scenario-Based Practice
+**Scenario 1: Service Not Starting** 
+Step 1: systemctl status
+Why: This will display the status 
+s
+Step 2: journalctl 
+why :this will display recent logs
+
+Step 3: systemctl start my-app
+Why: this will again start the application
+
+step 4: systemctl is-enabled
+why : to check is service is enabled
+
+**Scenario 2: High CPU Usage** 
+step 1: top
+why : this will display the top processes executing / htop has interactive display
+
+step 2: htop
+why : htop has interactive display where i can scroll also
+
+step 3 : ps aux --sort=-%cpu | head -10
+why : this will sort the process and then print first 10 processes
+
+**Scenario 3: Finding Service Logs** 
+step 1 : journalctl -u docker.io
+why : this will display the logs of docker
+
+step 2 :journalctl -u docker.service -n 50
+why : this will show last 50 lines
+
+step 3: journalctl -u docker.service -f
+why : this will show me the docker logs in real time
+
+**Scenario 4: File Permissions Issue** 
+step 1 : ls -l
+why : firstly check the permsission of file 
+
+Step 2 : chmod u+x file_name.sh
+why : then give execute perimission to user 
+
+step 3: ls-l
+why :rwxr--r-- this means owner got permission to execute