Senior Systems Administrator; Linux Security Clearance

Position: Senior Systems Administrator (Linux) with Security Clearance
Location: Waimea

Amentum is seeking a highly experienced Senior Linux System Administrator to oversee and manage enterprise-level Linux infrastructure in support of U.S. Navy operations within a Department of Defense (DoD) environment. This role requires deep technical expertise in Linux systems, leadership in secure system administration, and a strong working knowledge of Risk Management Framework (RMF) and NIST SP 800-53 controls. The ideal candidate will demonstrate the ability to lead teams, manage complex environments, and ensure cybersecurity compliance across classified and unclassified networks.

RESPONSIBILITIES:
* Administer and maintain Red Hat Linux (RHEL) and other Linux-based environments in classified and unclassified environments across Navy networks.
* Implement and maintain RMF security controls and ensure systems are compliant with DISA STIGs and DoD cybersecurity policies.
* Apply and manage patches and updates across all Linux systems in accordance with DoD and Navy patch management policies.
* Manage automated installation methods and system imaging (e.g., SCCM, VMware, Nutanix, Satellite, Ansible)
* Perform system hardening, patching, and vulnerability remediation using tools such as ACAS, ESS, and SCAP.
* Develop and maintain Power Shell scripts for automation of administrative tasks and system configuration.
* Support virtualization platforms (VMware, Hyper-V) and manage virtual infrastructure lifecycle.
* Collaborate with cybersecurity teams to support ATO packages, POA&Ms, and audit readiness.
* Maintain system documentation, configuration baselines, and standard operating procedures (SOPs).
* Provide mentorship to junior administrators and IT support staff.
* Participate in Change Control Boards (CCBs) and Configuration Management Boards (CMBs).
* Assist with incident response, forensic analysis, and system recovery efforts.
* Support backup and disaster recovery strategies using enterprise tools (e.g., Veeam, Commvault).
* Evaluate and recommend new Linux technologies and DoD-approved tools to improve system performance and security.
* Perform other duties as assigned. Physical Elements:
Lifting: 25 - 50lbs Positions:
Walking/Standing;
Crawling/Kneeling;
Stooping;
Sitting;
Frequent climbing Pushing/ Pulling: 25 - 50lbs Environmental:
Customer Contact;
Extended Work Day;
Confined Work Area;
Office Laboratory;
Field Assignment;
Inclement Weather MINIMUM QALUIFICATIONS

Experience:

* Advance knowledge and certification in both Windows Server and RHEL is considered highly desired
* Proficiency in automation tools and scripting (e.g., Power Shell, Bash, Python)
* VMware/Nutanix certification
* Knowledge/Administration of Trellix, Log Rhythm, and MDE
* Experience with DoD systems and infrastructure
* Knowledge of Cyber Security Methods and Techniques
* Knowledge of DoD IT systems, to include Windows, RHEL, and comprehensive infrastructure concepts

Education:

* Bachelor's degree and 7+ years of System Administration/IT experience
OR
* HS Diploma and 12 years of of System Administration/IT experience

* Advance certifications may be substituted for a degree or experience Required Training, Licenses and

Certifications:

* DoD 8570/8140 IAT II
* Red Hat Certified System Administrator (RHCSA) certification Security Clearance
Top Secret security clearance is required with T5 or equivalent (SSBI) investigation level. Applicants selected must be a US Citizen to apply for a Secret Security Clearance. Applicants selected either must currently possess a Secret clearance or will be subject to a government security investigation and must meet eligibility requirements to obtain clearance prior to commencement of employment and maintain a security clearance for access to classified information or Closed/Restricted Areas throughout duration of employment.

Compensation Details:
$105K - $145K The compensation range or hourly rate listed for this position is provided as a good-faith estimate of what the company intends to offer for this role at the time this posting was issued. Actual compensation may vary based on factors such as job responsibilities, education, experience, skills, internal equity, market data, applicable collective bargaining agreements, and relevant laws.

Benefits Overview:
Our health and welfare benefits are designed to support you and your priorities. Offerings include:
* Health, dental, and vision insurance
* Paid time off and holidays
* Retirement benefits (including 401(k) matching)
* Educational reimbursement
* Parental leave
* Employee stock purchase plan
* Tax-saving options
* Disability and life insurance
* Pet insurance

Note:

Benefits may vary based on employment type, location, and applicable agreements. Positions governed by a Collective Bargaining Agreement (CBA), the McNamara-O'Hara Service Contract Act (SCA), or other employment contracts may include different provisions/benefits. Original Posting:
02/17/2026 - Until Filled
Amentum anticipates this job requisition will remain open for at least three…