Senior Linux Systems Administrator — DoD RMF/HPC Specialist

Astrion; Columbia (MD); On-site; USD 145,000 - 165,000; Full time

Job summary

Astrion is seeking a Senior Linux Systems Administrator to build, secure, and sustain Linux servers, HPC clusters, and enterprise storage across multiple isolated networks in Columbia, MD. This on-site role requires an active TS/SCI clearance and DoD RMF/STIG compliance expertise.

The candidate will patch, harden, and operate RHEL systems, manage an HPC workload and NetApp storage, and automate with Bash, Python, and Ansible while maintaining security documentation and ATO readiness.

Qualifications

• Active TS/SCI clearance is required.
• Bachelor's degree in CS/IT or equivalent experience.
• 8+ years of Linux systems administration in DoD/classified environments.
• Deep RHEL expertise, scripting, and automation experience.
• DoD STIG compliance on Linux and HPC cluster administration.
• Experience with DoD RMF, discov ery and accreditation processes.
• Experience with enterprise storage (NetApp ONTAP) and offline patching.

Responsibilities

• Administer, patch, and sustain RHEL servers/workstations across multiple isolated networks.
• Hardening to STIGs, remediate findings, control configuration drift.
• Administer HPC cluster, compute nodes, PBS Professional, storage, and interconnect.
• Manage NetApp ONTAP storage, NFS/CIFS exports, backups, and capacity planning.
• Automate provisioning with Bash/Python/Ansible, including air-gapped systems.
• Patch air-gapped networks via offline repositories and trusted media.
• Enforce identity/access controls (LDAP/SSSD, Kerberos, FreeIPA/AD).
• Integrate Linux endpoints with CI/security tools and RMF monitoring.
• Contribute to ATO processes, STIG checklists, and risk assessments.
• Develop security artifacts and system documentation.

Skills

RHEL admin

Bash

Python

Ansible

LDAP/SSSD

Kerberos

STIG compliance

HPC cluster

NetApp ONTAP

RMF compliance

ACAS/SCAP

Air-gapped patching

Education

Bachelor's degree in Computer Science/IT or related field

Tools

PBS Professional

NetApp ONTAP

Kubernetes/ Podman

Red Hat Satellite

Nessus/SCAP

LDAP integration

Job description

Astrion is seeking a Senior Linux Systems Administrator to build, secure, and sustain Linux servers, HPC clusters, and enterprise storage across multiple isolated networks in Columbia, MD. This on-site role requires an active TS/SCI clearance and DoD RMF/STIG compliance expertise.

The candidate will patch, harden, and operate RHEL systems, manage an HPC workload and NetApp storage, and automate with Bash, Python, and Ansible while maintaining security documentation and ATO readiness.