# Linux System Administration & Automation 🐧⚙️

### ✅ What I worked on:

🔹 **User & Group Management**

* Created users and groups
    
* Configured sudo access
    
* Restricted SSH access for better security
    

🔹 **File & Directory Permissions**

* Applied precise permission controls using `chmod` and `chown`
    
* Verified access using `ls -l`
    

🔹 **Log File Analysis (AWK, grep, sed)**

* Searched errors with `grep`
    
* Extracted timestamps & log levels using `awk`
    
* Masked IP addresses with `sed`
    
* Identified most frequent log entries
    

🔹 **Volume & Disk Management**

* Mounted storage under `/mnt`
    
* Verified mounts using `df -h` and `mount`
    

🔹 **Process Monitoring**

* Managed background processes
    
* Monitored using `ps`, `top`, and `htop`
    
* Safely terminated processes
    

🔹 **Shell Scripting & Automation**

* Wrote a backup script using `tar`
    
* Added colored success output
    
* Automated backups using `cron`
    

💡 This week strengthened my understanding of how **Linux powers real DevOps environments**, from security and monitoring to automation.

📌 I’ll be sharing commands, scripts, and learnings soon on GitHub / Blog.

#90DaysOfDevOps  
#LinuxAdmin  
#DevOps  
#ShellScripting  
#Automation  
#SysAdmin  
#LearningInPublic

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## 🧠 (Optional) GitHub / Blog – Command Highlights

```plaintext
# User & Group
sudo useradd devops_user
sudo groupadd devops_team
sudo usermod -aG devops_team devops_user
sudo usermod -aG sudo devops_user

# Permissions
mkdir /devops_workspace
touch /devops_workspace/project_notes.txt
chmod 640 project_notes.txt

# Log Analysis
grep -i "error" Linux_2k.log
awk '{print $1, $2, $3}' Linux_2k.log
sed -E 's/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/[REDACTED]/g' Linux_2k.log

# Process
ping google.com > ping_test.log &
ps aux | grep ping
kill <PID>

# Backup Script
tar -czvf backup_$(date +%F).tar.gz /devops_workspace
```