After weeks of a lot of work with the Operating Systems Configuration subject of ASIR (UOC-Jesuits), I wanted to comprehensively compile all the techniques and practices we have carried out. This is not just a summary, but a field guide on how to manage IT infrastructures from the physical base to system logic.
1. Physical Infrastructure: Shielding against EMI
Every system starts with the hardware. In the case of the Club UOCX Readers project, located in an industrial estate with strong electromagnetic interference (EMI), component selection was critical.
Structured Cabling
We opted for Category 6a S/FTP cable. Unlike conventional UTP cable, S/FTP combines a general shielding of the cabling with an individual shielding for each twisted pair, eliminating the risk of packet loss due to interference.
Form Factors and Expansion
We analyzed motherboards to understand physical limitations:
- ATX (MSI B760 Gaming Plus): Maximum expansion with 4 memory slots and multiple PCIe 4.0 x16.
- Micro-ATX and Mini-ITX: Ideal for environments with reduced space but with more limited expansion capabilities.
Download practice AA1: Structure and components of a computer system
2. The Virtual Lab: VirtualBox in Detail
For the practices, we have set up a robust virtualization environment with VirtualBox.
- "W10+Linux" machine configuration: We assigned 4GB of RAM and 2 CPUs (on an i7-4790K) for a Windows 10 version 22H2 system.
- Extension Pack: Essential for supporting USB 2.0/3.0 dongles and the webcam in the *guest* system.
- Storage: Use of VDI format with 50GB of space to guarantee virtual disk flexibility.
Download practice AA2: Operating systems virtualization
3. User Administration in Ubuntu (Text Mode)
One of the most powerful practices was managing users and groups directly from the shell, applying strict security policies.
Commands and Best Practices
- Group creation: `sudo groupadd Presidencia`, `Tesoreria`, `Marketing`, etc.
- Name management: To maintain the capital letters of the names (such as "Santi" or "Marta"), we used `sudo adduser "name" --force-badname`.
- Group assignment: `sudo usermod -aG "Group" "User"` to ensure that each user has the appropriate permissions for their area.
User Policy and Passwords
- Santi (Presidencia): `!84lunAcielo`
- Marta (Tesoreria): `92_solramA`
- DavidOtero (Informatica): `7ghs2A010_`
Download practice AA3: Base software configuration (Ubuntu)
4. Process Control and Performance
Knowing what the system is doing at all times is vital for any ASIR administrator.
Monitoring Techniques in Ubuntu
1. List by CPU consumption: `ps -eo %cpu,command --sort=-%cpu` to identify the process requesting the most resources.
2. Tree structure: `pstree` to understand the parent-child relationships between processes.
3. Background: We practiced executing tasks in the *background* with `sleep 4 &` and managing heavy processes like `yes > /dev/null`.
Management in Windows 10
We also located specific processes (such as Notepad) to terminate them from the command line when the system was not responding.
Download practice AA4: Process management and monitoring
5. Networking: Connecting Virtual Worlds
The network challenge consisted of communicating two virtual machines (Ubuntu and Windows) by manually configuring TCP/IP.
- Manual configuration: We defined fixed IPs, network masks, and DNS (such as Google 8.8.8.8 or Cloudflare 1.1.1.1).
- Diagnosis: Intensive use of `ping` to verify latency and connectivity, and `ipconfig -all` (Windows) or `ifconfig/ip a` (Ubuntu) to validate the parameters.
6. Advanced Storage Management
Finally, we worked on data persistence and partitions.
Ubuntu and File Systems
- Structures: Creation of recursive directories with `mkdir -p` and backups maintaining permissions with `cp -a`.
- Links: We learned the critical difference between symbolic links (`ln -s`) and hard links (`ln`). If the "motards" file is deleted, the symbolic link is broken, but the hard link maintains access to the data because it points to the inode.
- Partitioning: We added a 10GB disk with GPT structure and configured automatic mounting in "read-only" mode via `/etc/fstab` for critical partitions like "Juegos" or "Trapicheos".
Windows 10
We practiced creating NTFS volumes (for videos, with 4096-byte allocation units) and FAT32 (for photos) on additional 5GB disks.
Download practice AA5: The file system and storage
Storage management is not just about making space, but about knowing which technology (GPT vs MBR, NTFS vs ext4) is appropriate for each use.
Conclusion and Final Reflections
This subject has been a true technical marathon that has changed my perspective on how software and hardware interact. Operating Systems Management is not just about installing Ubuntu or Windows; it's about understanding memory hierarchy, knowing how the kernel manages execution threads, and having the cool head to debug a segmentation fault from the command line.
I've learned that a good systems administrator must be versatile and curious by nature. It's not enough to know that the network works; we must understand why an S/FTP cable saves our lives in an industrial environment or how the ext4 file system manages inodes to avoid fragmentation. It has been demanding, with hours of configuring virtual machines and bash scripts, but the satisfaction of seeing a hybrid environment communicating perfectly is what really counts.
If you have arrived here reading this entire technical block, I tell you truly: you deserve a prize! 🏆 Since I'm feeling generous and want to share what I've learned, I'm leaving you an extra resource I created during the course to test everything we've seen about system performance.
🎁 Download your prize: Ultimate Laptop Optimization Guide
Do you have any questions about how to configure your virtual network or how to manage partitions in Linux? Leave a comment and let's talk!