Linux System Administrator

G6 Cyber Solutions; San Antonio (TX); On-site; USD 70,000 - 90,000; Full time

Job summary

G6 Cyber Solutions is seeking a motivated Linux System Administrator in San Antonio, Texas. In this role, you will manage and secure internal systems for military operations, ensuring compliance with Department of War standards while optimizing network infrastructure.

Required qualifications include system administration experience across Windows and Linux, along with CompTIA Security+ and Red Hat certifications. This opportunity is perfect for those keen on contributing to mission-critical projects.

Qualifications

• Experience in system administration, covering design, configuration, and installation of operating systems.
• Hands-on management of hardware and software for installation and upgrades.
• Ability to monitor resource usage and provide optimization recommendations.

Responsibilities

• Manage the security and maintenance of internal systems.
• Perform OS security configuration and monitoring.
• Document system infrastructure for multiple stakeholders.

Skills

System administration

Windows and Linux OS management

Network security

Command-line interfaces

Vulnerability scanning

Education

CompTIA Security+ certification

Red Hat Certified System Administrator (RHCSA)

Tools

SIEM tools

Intrusion Detection Systems

Job description

POSITION DESCRIPTION

G6 Cyber Solutions (G6CS) is at the forefront of delivering innovative technology solutions that enhance national security and support critical military operations. Our commitment to excellence drives us to develop and maintain cutting‑edge systems and capabilities in direct support of the warfighter.

Currently, G6CS is seeking a motivated and mission‑oriented Linux System Administrator to join our team in support of Air Force operations at Lackland AFB. In this role, you will be instrumental in managing and securing internal systems, ensuring compliance with Department of War (DoW) standards, and optimizing network infrastructure in a classified environment. If you thrive in a dynamic setting with a focus on cybersecurity and system reliability, this is an opportunity to contribute to mission‑critical projects that make a difference.

Required Experience

• Experience in system administration, including design, configuration, installation, and optimization of operating systems (Windows, Linux).
• Proven experience in managing hardware, software, and utilities for installation, modification, troubleshooting, maintenance, and upgrades of operating systems on servers.
• Experience in monitoring and analyzing resource usage to recommend enhancements to system capabilities and performance.
• Familiarity with developing accreditation documentation, including Overview 1, 2, and 3 (OV1, OV2, OV3) charts and graphs.
• Experience in restoring critical system services within service level agreement timelines of a system outage and managing software patching within specified timeframes (i.e. 3 business days for critical systems and 10 business days for routine patches).
• Experience in scanning computer networks for vulnerabilities and diagnosing network connectivity issues.
• Understanding of both Linux and Windows command‑line interfaces (CLI).

Nice‑to‑Have Experience

• Experience in Department of War intelligence communities.
• Experience with security features and/or vulnerabilities of various operating systems as defined by NSA, NIST, and/or USCYBERCOM.
• Experience in developing automated scripts for system monitoring and maintenance.
• Experience with Information Assurance (IA) vulnerability identification/remediation/testing and related network and system test tools (e.g., Security Content Automation Protocol (SCAP)).
• Experience with information security toolsets such as anti‑virus, Security Information and Event Management (SIEM), and/or Host‑based Intrusion Detection Systems/Network Intrusion Detection Systems (HIDS/NIDS).

What You Will Be Doing

• Manage the development, documentation, maintenance, and security of internal systems, including design, configuration, installation, administration, optimization, integration, and integrity.
• Perform network and system security administration, including operating system security configuration, performance monitoring, and account management best practices for MS Servers/Windows and Linux.
• Configure and assist in the design of system and network security.
• Track and monitor patching and STIG applications to the network servers to maintain network health.
• Provide support in restoring critical system services and ensure timely installation of applicable operating system and server software patches.
• Document system infrastructure for users, support personnel, developers, information assurance personnel, and accreditors.
• Managing networking switches, routers, and firewalls, including configuration, monitoring, and troubleshooting in DoD‑compliant environments to ensure secure data flow and network integrity.

Certifications

Minimum: CompTIA Security+ and Red Hat Certified System Administrator (RHCSA) or higher certification.

Nice‑to‑Have: Additional certifications in system administration or cybersecurity.