Linux installation, users, permissions, services, networking, shell scripting and troubleshooting.
What you will cover
Linux installation
users
permissions
services
networking
shell scripting
troubleshooting
Topic list from the institute's programme record.
Certification
Certificate terms for this programme are confirmed by the institute at admission. Any ADIVAS course-completion certificate is an institute certificate; it is not a university degree, an externally accredited qualification or a vendor certification (such as AWS or Microsoft) unless the institute states so in writing.
Curriculum 0.1 · Draft: written for ADIVAS and awaiting academic review and approval. Topics and weeks may change before your batch starts.
Your skill trail
You move through 4 stations. Each week builds one skill you can show, not just a topic you have heard.
1
Install and explore
Install Linux in a virtual machine and work comfortably with the file system and commands.
Week 1 Linux installation and first boot
Week 2 File system and command line
2
Users, permissions and software
Control who can do what, and manage packages and processes safely.
Week 3 Users, groups and permissions
Week 4 Packages, processes and storage
3
Services and networking
Run services with systemd and configure networking, SSH and a firewall.
Week 5 Services with systemd
Week 6 Networking, SSH and firewall
4
Automate and troubleshoot
Automate tasks with shell scripts and diagnose faults using logs and monitoring tools.
Week 7 Shell scripting and automation
Week 8 Monitoring, logs and troubleshooting project
★
Small Office Server Build
Your project, reviewed by a trainer.
The ADIVAS mastery ladder: how each skill is recognised
Explored You have seen the idea and tried a first example.
Practising You can do it with hints and keep improving.
Proficient You complete the weekly practical task correctly on your own.
Proven You apply it in a project reviewed by your trainer.
Skill-level tracking is being added to the learner workspace. Your trainer already reviews weekly practical work.
What you will be able to do
Install a Linux distribution in a virtual machine, partition a disk and explain the boot process.
Navigate the file system and manage files, text and processes with command-line tools.
Create users and groups and set file permissions and sudo access using least privilege.
Install, update and remove software with the package manager and manage services with systemd.
Configure IP networking, DNS and SSH key login, and apply a basic firewall.
Write shell scripts with variables, conditions and loops to automate routine admin tasks and backups.
Read logs, monitor disk, memory and CPU, and troubleshoot a failing service step by step.
Who it suits
School Senior school students curious about how servers and free operating systems work; no prior command-line knowledge needed.
College Computer science, IT and diploma students who want hands-on server skills before cloud, DevOps or networking courses.
Professional Support engineers, hardware and network technicians and developers who need to administer Linux servers at work.
Prerequisites: Basic computer skills: files, folders, installing software. Ability to read simple technical English; no programming needed. Tools: VirtualBox or another free hypervisor, A current Ubuntu Server or Debian LTS image, Terminal and OpenSSH client, nano or vim text editor, A laptop with 8 GB RAM recommended.
Weekly plan
Install and explore Weeks 1–2
Week 1: Linux installation and first boot
Theory
What Linux is: kernel, distribution, shell
Virtualisation and choosing a server distribution
Disk partitions, file system types and the boot process
Lab
Create a VirtualBox VM, install Ubuntu Server with a separate home partition, log in and run uname -a, lsblk and df -h to record what was installed.
Homework
Write half a page on the boot sequence from power button to login prompt, and take a snapshot of the VM.
Deliverable
A working VM with a snapshot named 'clean-install' and a one-page install record.
Weekly checkpoint
Sequence the boot stages; short practical: show disk layout with lsblk and explain each line.
You will be able to
Install a Linux distribution in a virtual machine, partition a disk and explain the boot process.
Week 2: File system and command line
Theory
Directory layout: /etc, /var, /home, /usr
Navigation, copy, move, remove, find and links
Viewing and searching text: cat, less, grep, head, tail, pipes and redirection
Lab
Build a practice directory tree, search /etc for settings with grep, count lines with wc, and chain commands with pipes and redirection into a report file.
Homework
Use the man pages to find three new options for ls, find and grep and document one example each.
Deliverable
A commands cheat sheet with 20 tested commands and a sample output of each.
Weekly checkpoint
Command-line practical: find all .conf files modified in the last day and count the lines in each.
You will be able to
Navigate the file system and manage files, text and processes with command-line tools.
Users, permissions and software Weeks 3–4
Week 3: Users, groups and permissions
Theory
Users, groups, /etc/passwd and /etc/shadow
Read, write, execute and octal permission notation
chmod, chown, umask and sudo with least privilege
Lab
Create a team of three users in two groups, make a shared project folder where only the group can write, and give one user limited sudo rights using a drop-in file.
Homework
Audit your home directory for files that are world-writable and fix them.
Deliverable
A permissions matrix for the shared folder with commands used and test results.
Weekly checkpoint
Scenario: a user cannot edit a file; identify the owner, group and mode problem and fix it.
You will be able to
Create users and groups and set file permissions and sudo access using least privilege.
Week 4: Packages, processes and storage
Theory
apt and package repositories, updates and removing packages
Processes, signals, ps, top and kill
Mounting disks, fstab and checking free space
Lab
Install nginx and htop with apt, find and stop a runaway process created by a test loop, add a second virtual disk, format it and mount it persistently through fstab.
Homework
Write a safe update routine: refresh package lists, review upgrades, apply them and record what changed.
Deliverable
A tested document showing the package, process and mount steps with outputs.
Weekly checkpoint
Match commands to tasks; practical: add and mount a new disk without breaking boot.
You will be able to
Install, update and remove software with the package manager and manage services with systemd.
Services and networking Weeks 5–6
Week 5: Services with systemd
Theory
Units, targets and the systemctl command
Starting, enabling, masking and reading service status
Writing a simple custom service unit and restart policy
Lab
Run a small web page with nginx, write a systemd unit for a tiny script, make it start at boot and restart on failure, then kill it to prove it recovers.
Homework
Document how to disable an unneeded service and why that reduces the attack surface.
Deliverable
A custom service unit file with a screenshot of it recovering after a forced stop.
Weekly checkpoint
Troubleshoot a service that is enabled but failed; read systemctl status and fix the cause.
You will be able to
Install, update and remove software with the package manager and manage services with systemd.
Week 6: Networking, SSH and firewall
Theory
IP address, subnet mask, gateway and DNS in Linux
ip, ping, ss, dig and curl for diagnosis
SSH key login, disabling password login and a basic ufw firewall
Lab
Give the VM a static address with netplan, connect from the host using SSH keys, disable password authentication, and allow only SSH and HTTP through ufw.
Homework
Test which ports are open from the host and explain each open port in writing.
Deliverable
A network configuration record, SSH key setup notes and the final firewall rule list.
Weekly checkpoint
Diagram question on the path of a web request; practical: diagnose a VM that cannot resolve names.
You will be able to
Configure IP networking, DNS and SSH key login, and apply a basic firewall.
Automate and troubleshoot Weeks 7–8
Week 7: Shell scripting and automation
Theory
Variables, arguments, conditions and exit codes
Loops and functions; quoting and safe habits
Scheduling with cron and a simple backup with tar and rsync
Lab
Write a backup script that archives a folder with a dated name, keeps only the last five archives, logs success or failure, and schedule it with cron.
Homework
Extend the script to check free disk space before running and exit with a clear message if it is low.
Deliverable
A commented script, its cron entry and a log showing three successful runs.
Weekly checkpoint
Read a short script and predict its output; fix a script with a quoting bug.
You will be able to
Write shell scripts with variables, conditions and loops to automate routine admin tasks and backups.
Week 8: Monitoring, logs and troubleshooting project
Theory
journalctl and /var/log, reading errors in order
Monitoring CPU, memory and disk with top, free, df and iostat
A systematic troubleshooting method: observe, hypothesise, test, fix, document
Lab
Trainer breaks the server in four ways (full disk, wrong permission, stopped service, blocked port); find and fix each, using logs and a written fault record.
Homework
Write a one-page runbook describing how to respond to a full-disk alert.
Deliverable
The final server build and troubleshooting report presented to the class.
Weekly checkpoint
End-of-course practical: fix two injected faults in 30 minutes and explain the reasoning.
You will be able to
Read logs, monitor disk, memory and CPU, and troubleshoot a failing service step by step. Create users and groups and set file permissions and sudo access using least privilege. Configure IP networking, DNS and SSH key login, and apply a basic firewall.
Sample lessons
Week 3
File permissions and least privilege
Every Linux file has an owner, a group and three permission sets: for the owner, for the group and for everyone else. Each set can allow read (r), write (w) and execute (x). Permissions are written as letters like rwxr-x--- or as numbers: r is 4, w is 2 and x is 1, so rwx is 7, r-x is 5 and no access is 0. Least privilege means giving each person only the access they need, so a mistake or a stolen account cannot do much damage.
Who
r (4)
w (2)
x (1)
Owner (u)
yes
yes
yes
Group (g)
yes
no
yes
Others (o)
no
no
no
Mode 750: owner rwx, group r-x, others none.
Step by step
Run ls -l to see the owner, group and mode of a file.
Create a group with groupadd and add a user with usermod -aG.
Change the group of a folder with chown :groupname folder.
Set the mode with chmod 770 or chmod g+w.
Test by switching user with su or sudo -u and trying to read and write.
In real life
In an office, accounts staff need to edit the salary sheet but trainers must not even read it. A group for accounts with a folder set to 770 lets one team work and keeps everyone else out.
Worked example
Problem. File report.txt has mode 640, owner anitha and group office. Can user murugan (in group office) write to it? Can user guest (not in office) read it?
Solution. 640 means owner rw-, group r--, others ---. Murugan is in the group so he can read but not write. Guest is in 'others' with no permission, so guest cannot read it.
Common mistakes
Using chmod 777 to make an error go away, which gives everyone full access.
Forgetting that a user must log in again for a new group membership to take effect.
Try it yourself
Convert rwxr-x--- to octal and explain who can do what.
Create a folder where the group can add files but only the owner can delete them (hint: sticky bit).
Week 8
A calm method for troubleshooting a failing service
When a service fails, guessing makes things worse. A reliable method is to observe first, then form one idea, test it, fix it and write it down. On Linux, observation means checking whether the service is running, reading its recent log lines, and checking the basics of disk space, permissions and network ports. Most faults are found in the first error line of the log, not in the last one.
1Observe the symptoms and logs
2Form one hypothesis
3Test and fix one change
4Verify and document
↻
Change one thing at a time and record it.
Step by step
Run systemctl status servicename and note the state and the last log lines.
Read more detail with journalctl -u servicename -n 50.
Check disk space with df -h and ports with ss -tulpn.
Change one thing, restart the service and check again.
Write the cause, fix and how to prevent it in your fault log.
In real life
A shop's billing web page stops at 10 am. The admin finds nginx failed because the disk was full of old log files; clearing them and adding log rotation fixes it and prevents a repeat.
Worked example
Problem. nginx fails to start and the log says 'bind() to 0.0.0.0:80 failed (98: Address already in use)'. What do you do?
Solution. Another process is already using port 80. Run ss -tulpn | grep :80 to find it. If it is a duplicate web server, stop and disable it, then start nginx again and confirm with systemctl status.
Common mistakes
Restarting the service again and again without reading the log.
Changing several settings at once so you cannot tell which one fixed the fault.
Try it yourself
List the first four commands you would run when a website on your server is not loading.
Write a fault record for a service that failed because of a wrong file permission.
Try the questions
The same skills are asked at three levels: School (Classes 6–12), College and Professional. Switch the level and the language (English or Tamil), and say how sure you are before you check: knowing what you are unsure about is part of learning.
Classes 6–12: everyday examples, no prior knowledge. Practice only. Nothing here is graded or saved.
Question 1 / 4 · Understand what an operating system does
A school librarian lends books and records who took which book. In a computer, which part does a similar job of sharing the machine's resources among programs?
Projects
Small Office Server Build
A small Madurai coaching centre needs a Linux file and web server for its staff. Build it from scratch in a virtual machine, secure it sensibly and prove it can recover from faults.
Tasks
Install the server, create three staff users in two groups with a shared folder that only the group can write.
Install nginx, run it as an enabled service and serve a notice page; open only SSH and HTTP in the firewall.
Set up SSH key login for one user and disable password login.
Write a cron-scheduled backup script that keeps five dated archives and logs each run.
Break and fix the server twice and record both faults in a troubleshooting log.
Only group members can write in /srv/centre; the web page loads on port 80; password SSH login is refused; five backup archives exist; the troubleshooting log has two entries with cause and fix.
How it is assessed
Criterion
Weight
Users, groups and permissions correct
20%
Services and firewall configured securely
25%
Backup script and cron working
20%
Troubleshooting log quality
20%
Documentation and clear explanation
15%
Stretch challenge: Add a script that emails or logs a warning when disk use passes 80 percent, and document how you would restore from a backup.
How you are assessed
Each week: six short questions (concepts, command prediction and one diagram question), one timed command-line task in the lab VM and a short lab note recording the commands used and what was learned.
Practical work. Learners build and fix systems in their own virtual machine; the trainer checks outcomes with a command checklist (users, permissions, service state, firewall, backups) and reviews the lab notes.
What trainers look for
Weight
Working, correct configuration
40%
Security and least-privilege choices
20%
Troubleshooting method and logs
20%
Documentation and explanation
20%
Where this can lead
Prepares you for junior Linux support and system administration tasks.
Builds the foundation for cloud, DevOps and network engineering courses.
These describe skills you will build. ADIVAS does not guarantee jobs, placement or salary.
