Kubernetes / Storage
RKE2 Cluster & Longhorn Investigation
Reviewed cluster health, Longhorn volume and replica states, instance-manager workloads, and resource reservation versus observed CPU usage to help narrow infrastructure issues.
IT Systems · Infrastructure · Technical Support
Walid Umar.
Senior IT Sysadmin and vocational IT educator with 15+ years of experience across Linux and Windows infrastructure, virtualization (Proxmox, Nutanix, Sangfor), networking, and technology education. Currently supporting server and hypervisor infrastructure and DevOps work for a university academic information system. Focused on reliable services, clear documentation, and practical problem-solving.
About Me
Reliable systems. Practical solutions.
A combination of hands-on infrastructure experience, structured troubleshooting, and the ability to explain technical concepts clearly.
I work across Linux servers, networking, virtualization, containers, databases, monitoring, and application support. My approach is to investigate symptoms methodically, review logs and system metrics, isolate likely causes, document findings, and recommend maintainable solutions.
Alongside technical operations, my work as a vocational IT educator and learning facilitator strengthens my communication, documentation, and user-support skills. I also mentor SMK students preparing for LKS competitions at provincial and national levels, especially in IT Network System Administration and Cloud Computing. I create technical learning materials and tutorials covering Linux, servers, networking, and virtualization.
I am interested in remote opportunities in Linux/System Administration, Application Support, IT Service Desk, Infrastructure Support, Cloud Support, and Technical Documentation or Training.
15+ yearsIT and technology-related experience
LinuxDebian and Ubuntu Server
InfrastructureVirtualization, containers and networking
EducationTechnical training and documentation
HypervisorsProxmox VE · Nutanix AHV · Sangfor HCI
748+Technical articles on walidumar.my.id since 2022
Working approach: structured troubleshooting, root-cause investigation, service reliability, security awareness, documentation, and continuous learning.
Core Competencies
Technical skills
A cross-functional skill set for support, systems, and infrastructure roles.
Systems & Linux
Debian, Ubuntu Server, Windows Server & Active Directory, systemd, DNS/DHCP/web/database services, shell troubleshooting, RAID/ZFS, performance tuning.
Virtualization & Containers
Proxmox VE, Nutanix (AHV/Prism), Sangfor HCI, KVM/LXC, Docker, Kubernetes/RKE2, clustering and HA, snapshot vs backup vs DR.
Networking & Security
LAN/WAN, TCP/IP, VLAN, OSPF/BGP, NAT, VPN, firewall, Cisco, MikroTik, SSH hardening, 2FA (TOTP), Fail2Ban, network segmentation.
Databases & Applications
PostgreSQL, MariaDB/MySQL, Nginx, web application troubleshooting, SQL fundamentals, service and connection analysis.
Monitoring & Observability
Prometheus, Grafana, metrics review, capacity investigation, alerting concepts, system and application log analysis.
Automation & DevOps
Ansible, Terraform, Git, CI/CD concepts, cloud-init, Debian preseed and Ubuntu autoinstall, Bash scripting, idempotent configuration.
Web, CMS & E-Learning
Moodle administration and development, WordPress, Drupal, school websites, web design, Nginx/PHP-FPM hosting.
Linux Ecosystem & Open Source
Debian, Ubuntu, CentOS, Red Hat, repository management, mass Linux installation, Linux distribution development (Saronde OS).
Instructional Design
Problem-based and project-based learning (PBL/PjBL), teaching modules, lesson plans, assessment banks, UKK and LKS preparation.
Managed Hosting & Migration
VPS and dedicated server setup, provider-to-provider migration (AWS, GCP, DigitalOcean, Vultr and local providers), automated backups, malware cleanup, hardening, Nagios monitoring.
Support & Documentation
Incident investigation, root-cause analysis, technical writing, user guidance, learning materials, knowledge sharing.
Technology Map
Layered infrastructure expertise
From the network edge up to the application, with security, observability, and automation applied across every layer.
Applications
SIAKADMoodleNginxPHP-FPM
Databases
PostgreSQL + PatroniMariaDB/MySQL
Containers & Orchestration
DockerKubernetes / RKE2Longhorn
Operating Systems
DebianUbuntu ServerWindows Server / AD
Virtualization & Storage
Proxmox VENutanix AHVSangfor HCIZFS
Networking
MikroTikCiscoVLANOSPF / FRRVPN
Troubleshooting methodology
A repeatable, evidence-based workflow — diagnose first, change later.
1SymptomDefine the problem and its scope
2EvidenceCollect logs, metrics, configs
3HypothesisList probable causes
4TestVerify with safe diagnostic commands
5Root CauseConfirm the real source
6FixApply the safest solution first
7VerifyProve the result works
8PreventDocument and add safeguards
Selected Technical Work
Troubleshooting & infrastructure projects
Practical investigations and design work drawn from server, network, and application environments.
Database / HA
PostgreSQL & Patroni Diagnostics
Examined leader and replica status, streaming replication, PostgreSQL activity and connection counts, and database logs while investigating application access and login symptoms.
Monitoring
Prometheus & Grafana Operations
Investigated storage pressure in Grafana's data directory and reviewed monitoring signals and resource metrics to support capacity and service-health troubleshooting.
Linux / Web
Fail2Ban, systemd, aaPanel & Nginx
Reviewed service states, journal logs, socket paths, jail status, and web-server configuration while diagnosing inconsistent Fail2Ban status and website maintenance behavior.
Virtualization / Network
Proxmox VE & Network Infrastructure
Worked through VLAN-aware bridge concepts, backup/restore workflows, FRR with OSPF routing, and virtual lab requirements for network and server administration.
Solution Design
Moodle CBT Infrastructure Planning
Designed a three-server architecture concept for a school examination environment serving approximately 1,500 students, considering web delivery, PHP-FPM, database load, HTTPS, and server capacity.
Project descriptions summarize troubleshooting and design activities. They do not imply that every investigated issue was conclusively resolved or that every proposed architecture was deployed in production.
Experience
Professional background
Infrastructure practice and education experience that complement one another.
Senior IT Sysadmin — UNG Partner Company
Manage server and hypervisor infrastructure (Nutanix, Proxmox, Sangfor) and serve as Sysadmin/DevOps for the SIAKAD UNG academic information system at Universitas Negeri Gorontalo, with attention to availability, backup, security, and change management.
System & Network Administration
Practical administration and troubleshooting across Linux servers, network services, virtualization, databases, monitoring, security tools, and application infrastructure. Experience includes investigating operational issues and documenting technical findings.
Vocational IT Educator & Learning Facilitator
Teaching and facilitating computer networking and systems topics, developing technical learning materials, guiding hands-on practice, and explaining complex concepts in a structured and accessible way.
Technical Content Creator
Author of 748+ tutorials on walidumar.my.id (Linux, servers, networking, security, UKK and LKS ITNSA preparation) and video content on YouTube. Also offers Linux Fundamental classes and sysadmin services.
LKS Competition Coach — Provincial & National Levels
Mentor vocational high school (SMK) students preparing for Lomba Kompetensi Siswa (LKS) competitions at provincial and national levels. Coaching focuses on IT Network System Administration and Cloud Computing, including hands-on lab practice, technical troubleshooting, scenario-based exercises, and competition readiness.
2006–2009
SMK Negeri 1 Kota Gorontalo — TKJ
Computer and Network Engineering
2009–2013
Bachelor's in Information Systems — Universitas Negeri Gorontalo
Information Systems study programme, Informatics Engineering department
2009–2012
Network Development — Planner & Developer
Built small-scale networks for schools, cafés and eateries, and an inter-school intranet
2012–Present
TKJ Educator & School Server/Network Admin
Computer Systems, Basic Networking, Server Administration, Web Design; LKS coaching
2014 onward
MikroTik RouterOS & Cisco
Deepening router and switch implementation; MikroTik and Cisco trainer
2016–2019
YouTube creator & tutorial author
IT networking tutorials on a personal YouTube channel and blog
2022
walidumar.my.id blog launched
Now 748+ articles on Linux, servers, networking and security
Present
Senior IT Sysadmin
Server, hypervisor and DevOps work for SIAKAD UNG
Blog, Learning Tools & Services
walidumar.my.id — sharing what I practice
A technical blog and interactive learning tools built from real server work and TKJ classrooms.
748Technical articles published
27Categories
2022Writing consistently since
LPIC-1Linux Fundamental class (certification prep)
Articles by category
Categories overlap, so totals exceed the article count.
Interactive learning tools
CLI Simulator (MikroTik & Cisco)
Browser-based command-line practice for router configuration.
Linux Bash Simulator
Interactive terminal practice for Linux commands.
Cisco VLAN Configuration Simulator
Topology-based VLAN lab for students.
Routing Protocol Lab
Hands-on routing exercises (Net-Lab-TKJ).
IP Address & Subnet Simulator
Calculate and visualize subnet blocks.
DLBD Debian Offline Repository
Offline Debian repository for labs and LKS ITNSA practice.
Recent writing
Services & classes
- Managed server servicesVPS setup, migration, backup, monitoring, malware cleanup
- Private Linux Fundamental courseLPIC-1
- Channel membership & UKK/LKS ITNSA videosYouTube
Recognition & Contributions
Achievements, open source & learning materials
Competition results, community projects, and teaching resources shared publicly.
🏆
1st Place — IOSAIOSA 2013, Jakarta🥉
3rd Place — Blog WritingSLiMS Commit 2014🎓
PKM Community ServiceOSORA (Open Source untuk Rakyat), 2012–2013🐧
Mass Linux Installation Award2013🎤
SpeakerICT and technology seminarsOpen source projects & communities
Saronde_OSGorontalo Linux distribution
Saronde_AppsGorontalo culture app
Kamus GorontaloGorontalo language dictionary app
MoodleE-learning development and admin
AKBER & KSLOpen source community volunteer
Published learning materials
Number of slides per document, available on SlideShare ↗
Education & Additional Information
Background
Bachelor's Degree in Information Systems
Universitas Negeri Gorontalo · Indonesia
Languages: Indonesian (Native), English (Proficient)
Technical interests: Linux infrastructure, reliable application services, observability, network engineering, virtualization, cloud technologies, technical education, and knowledge sharing.
Let's Connect
Have a remote IT opportunity?
Open to roles in system administration, application support, infrastructure support, technical support, and technical documentation or training.
Email Me ↗