Senior Redhat Linux Systems Administrator

The One 23 Group; Herndon (VA); On-site; USD 120,000 - 170,000; Full time

Job summary

The Senior Linux Systems Administrator at The One 23 Group provides Tier II/III administration for Red Hat Enterprise Linux and UNIX environments supporting JSSC Enterprise Services. Based primarily at the Pentagon, this role covers server administration, patching, security compliance, backup coordination, and on-call rotation.

The position requires an active Top Secret clearance, eligibility for SIPRNet access, and the ability to relocate to Site-R within 12 hours for COOP exercises or

Qualifications

• Active Top Secret security clearance with eligibility for SIPRNet access.
• U.S. citizenship required.
• At least 10 years of IT experience supporting complex systems and operations.
• Advanced UNIX/Linux server administration experience (preferably RHEL).
• Expertise in systems administration, architecture, integration, and monitoring.
• Current DoD IAT Level II certifications such as Security+, CySA+, GSEC, GICSP, SSCP, CCNA Security or equivalent.

Responsibilities

• Administer and maintain Red Hat Enterprise Linux and UNIX servers across production, test, and development environments.
• Perform account administration, OS maintenance, monitoring, and troubleshooting.
• Engineer and sustain Linux server hardware, OS, and software for mission-critical environments.
• Test and deploy patches through approved change-control processes.
• Apply DISA STIGs and support vulnerability remediation and security compliance.
• Support backup, disaster recovery, and continuity-of-operations requirements.
• Monitor system health, performance, capacity, and trends.
• Coordinate with government leads, admins, cybersecurity, and external support.

Skills

Top Secret clearance

UNIX/Linux administration

DoD IAT Level II certification

12x5 operations readiness

On-call/COOP readiness

Tools

VMware

Job description

At The One 23 Group, our mission is to set the benchmark for excellence in government services. We empower our clients in the Department of War, Intelligence Community, and Federal Civilian sectors to excel with our advanced capabilities. Our dedication lies in fostering a people-first culture, underpinned by steadfast ethical principles. Embracing innovative technologies and process improvements, we are steadfast in our journey toward a future that is both bright and transformative.

Our expertise spans Enterprise IT, Mission IT and Cyber. With our global footprint, we place a strong emphasis on nurturing our people and culture, which forms the core of our successful strategies in leadership and financial management. We pride ourselves on our extensive experience and effective approach, ensuring that we lead with both innovation and integrity.

Position Summary

The Senior Linux Systems Administrator provides Tier II/III administration and operational support for Red Hat Enterprise Linux (RHEL) and UNIX server environments supporting JSSC Enterprise Services. Based primarily at the Pentagon, this position supports GCCS-J and JPES mission environments across production, test, and development systems. Responsibilities include server administration, troubleshooting, patching, performance monitoring, security compliance, backup and recovery coordination, configuration management, and technical documentation.

The position requires an active Top Secret clearance, eligibility for SIPRNet access, participation in a 24/7 on-call rotation, and the ability to support continuity-of-operations requirements at Site-R when designated.

Requirements

Required Qualifications

• Active Top Secret security clearance with eligibility for SIPRNet access.
• U.S. citizenship.
• At least 10 years of relevant IT experience providing technical support and solutions for complex systems and operational environments.
• Advanced experience administering UNIX/Linux servers, preferably Red Hat Enterprise Linux.
• Expertise in systems administration, systems architecture, systems integration, network systems management, or a related technical discipline.
• Current certification meeting DoD IAT Level II requirements, such as Security+, CySA+, GSEC, GICSP, SSCP, CCNA Security, or another approved certification.
• Ability to work independently, exercise sound technical judgment, and develop solutions to complex IT problems.
• Ability to support 12x5 operations and participate in a 24/7 on-call rotation.
• Ability to respond within two hours of notification when on call.
• Ability to relocate to Site-R within 12 hours for COOP exercises or real-world contingencies when designated as an Emergency Relocation Group member.
• Ability to perform planned maintenance, repairs, and upgrades outside normal business hours when required.

Duties And Responsibilities

• Administer and maintain Red Hat Enterprise Linux and UNIX servers across production, test, and development environments.
• Perform account administration, operating system maintenance, resource monitoring, log analysis, performance tuning, storage support, and system troubleshooting.
• Engineer, configure, and sustain Linux server hardware, operating systems, and supporting software for mission-critical environments.
• Test and deploy operating system, COTS, GOTS, security, and IAVA-related patches through approved change-control processes.
• Apply DISA STIGs and support vulnerability identification, remediation, and security compliance activities.
• Support backup and recovery coordination, disaster recovery, and continuity-of-operations requirements.
• Monitor system health, availability, performance, capacity, and operational trends.
• Test hardware upgrades, software upgrades, patches, IAVAs, and configuration changes in non-production environments before implementation.
• Perform approved maintenance, repairs, and upgrades during scheduled non-business hours.
• Document, track, troubleshoot, and resolve incidents through the assigned ticketing system.
• Support ITIL-aligned incident, problem, change, and configuration management processes.
• Develop and maintain configurations, SOPs, implementation procedures, maintenance records, test plans, test reports, operational logs, and runbooks.
• Coordinate with government leads, system administrators, database administrators, application teams, cybersecurity personnel, and external support organizations.
• Recommend improvements to system administration and IT operations based on industry and ITIL best practices.

Preferred Qualifications

• Current Linux+, Security+, CySA+, CCNA Security, GSEC, GICSP, SSCP, or other certification meeting DoD IAT Level II requirements
• Experience administering RHEL in classified Department of Defense operational environments.
• Experience supporting DISA, GCCS-J, JPES, or comparable command-and-control mission systems.
• Experience with Linux shell scripting, automation, and system administration tools.
• Experience applying DISA STIGs, IAVAs, security patches, and vulnerability remediation measures.
• Experience with VMware or another enterprise virtualization platform.
• Experience with enterprise monitoring, logging, performance analysis, and capacity-planning tools.
• Experience with backup and recovery, storage coordination, disaster recovery, and COOP support.
• Experience supporting ITIL-based incident, problem, change, and configuration management.
• Experience developing SOPs, runbooks, technical documentation, and system configuration records.