TEDDY KWASI OSEI - Linux System Administrator - Qualous Technologies

Summary

Detail-oriented Linux Engineer with 8 years of hands-on experience managing and securing Linux systems in both on-premises and cloud environments. Known for a strong ability to troubleshoot issues, maintain system stability, and improve overall performance and efficiency.

Overview

8

years of professional experience

1

Certification

Work History

Linux System Administrator

Qualous Technologies

Dallas, Texas

03.2025 - Current

Provisioned new servers and applied ongoing patches to keep systems secure and current.
Analyzed and resolved network issues, focusing on TCP/IP communication and connectivity challenges.
Handled user account management across standalone and domain-integrated servers, maintaining accurate permissions and secure access.
Improved system security by disabling direct SSH login for the root user.
Maintained Linux file systems while enforcing security controls to protect sensitive data and ensure system integrity.
Configured user shell environments by customizing initialization files such as .bashrc and .bash_profile.
Set up cron jobs to handle repetitive administrative and maintenance tasks automatically, helping save time and improve consistency.
Supported software teams on a daily basis, troubleshooting issues and enhancing development environments to improve overall productivity.
Enhanced server security by configuring detailed firewall rules to limit exposure and better control network traffic.
Set up RAID configurations on physical servers to enhance storage reliability and improve overall performance.
Improved system security by enforcing password aging policies and configuring sudo access based on the principle of least privilege.
Monitored server performance and health using Prometheus, quickly responding to alerts to address system or process failures.

Linux System Engineer

Department Of Defence

El Paso, TX

10.2018 - 02.2025

Installed and configured Linux operating systems on Dell physical servers, ensuring systems were properly set up and hardened for security and stability.
Set up SSH with key-based authentication to strengthen security and minimize the need for password-based access.
Set up local storage with partitioning and LVM for better volume management.
Managed VMware ESXi environments on bare-metal servers, fine-tuning configurations to keep systems stable and running smoothly. Created custom Bash scripts to automate routine maintenance and reduce manual effort.
Provided 24/7 on-call support, responding quickly to production issues to ensure systems remained available and running smoothly.
Set up and managed user access across systems and domains, using Active Directory to centralize authentication and streamline identity management.
Maintained and supported both virtual and physical servers, ensuring systems ran reliably and efficiently.
Maintained reliable network connectivity on Red Hat systems by troubleshooting and resolving TCP/IP configuration issues.
Set up and managed NFS file systems, providing dependable shared storage that could be accessed by multiple clients.
Developed Ansible playbooks to automate configuration tasks and streamline day-to-day system administration.
Supported Windows Server environments on Dell hardware, keeping systems up to date, managing server roles, and maintaining consistent performance.
Managed Linux virtual machines on VMware ESXi and vCenter, ensuring efficient resource allocation and keeping systems stable and reliable.
Connected Linux and Windows servers to Microsoft Active Directory, enabling centralized authentication and easier management of user access and resources.
Performed capacity planning and fine-tuned system performance to keep resources running efficiently and support overall system stability.
Used Zabbix to monitor servers proactively, helping identify and resolve potential issues early before they impacted system performance.
Implemented system hardening measures to minimize vulnerabilities and strengthen overall security, aligning with organizational policies and best practices.
Handled and resolved network and performance issues across multiple environments, improving efficiency and keeping operations running smoothly.
Used Red Hat Satellite to streamline patch management and automate software deployments, helping keep systems consistent, up to date, and easy to maintain.
Collaborated with security teams to roll out monthly updates and patches, helping maintain compliance while keeping systems stable and reliable.
Set up and maintained LAMP environments on CentOS 7, using Apache, MySQL, and PHP to support development and testing workflows.
Performed critical system recovery and maintenance in single-user mode, helping minimize downtime and quickly restore system functionality.
Implemented and maintained Samba to provide secure, reliable file sharing between Linux and Windows systems.
Used Jira to track service requests and incidents, helping streamline workflows and ensure issues were resolved quickly.
Created and maintained detailed server documentation in Confluence and SharePoint to support smooth operations and ensure continuity.
Ran scheduled backups using Veeam, ensuring data remained secure and reliable while supporting smooth and efficient disaster recovery.
Built and maintained scalable AWS infrastructure, leveraging load balancing and auto-scaling to ensure strong performance and consistent uptime.
Compiled and presented weekly reports on system health and performance to leadership, helping guide strategic decisions.
Simplified the provisioning and management of AWS EC2 instances, improving scalability and overall system efficiency.

Education

Bachelor of Science -

Devry University of New York

Skills

Operating Systems: Red Hat Enterprise Linux and CentOS 7/8, Windows Server 2016, Windows Server 2019, and Windows 10
Cloud Platforms: Amazon Web Services (AWS)
Infrastructure & Enterprise Applications: Apache HTTP Server, Active Directory, Domain Controllers, Red Hat Satellite Server, LAMP stack, LDAP, NFS, SFTP, and Samba
Scripting & Automation: Bash/Shell scripting, Ansible, and Red Hat Satellite automation
Monitoring & Security Tools: Zabbix, Nessus, OpenSCAP, STIG compliance, Qualys, and Leapp
Networking: DHCP, TCP/IP, DNS, SSH, TCP/UDP, and SMTP
Virtualization: VMware vCenter and VMware ESXi
Containerization: Docker and Podman
Other Tools & Platforms: iDRAC, Microsoft 365, Outlook, Jira, Confluence, Microsoft Teams, and Veeam