Systems Administrator; Windows, Unix, Linux Security Clearance

Position: Systems Administrator (Windows, Unix, Linux) with Security Clearance
Sentar is proud to be an employee-owned company, fostering a culture of empowerment, collaboration, and innovation. Sentar is dedicated to developing the critical talent that the connected world demands to create solutions to address the convergence of cybersecurity, intelligence, analytics, and systems engineering. We invite you to join the team where you can build, innovate, and secure your career. Sentar is seeking a Systems Administrator (Windows, Unix, Linux) in Charleston, SC!

Role

Description:

The Systems Administrator (Windows, Unix, Linux) is responsible for managing and maintaining both Windows and Linux-based systems and servers. This role ensures the stability, integrity, and efficient operation of organizational information systems. The administrator applies proven communication, analytical, and problem-solving skills to identify, communicate, and resolve technical issues, while providing end-user support and performing sustainment tasks to maintain operational readiness and system availability.

Key Responsibilities
* Install, configure, and maintain Windows Server (2016, 2019, 2022) and Linux (RHEL, Ubuntu, CentOS, or similar) servers and components.
* Administer Active Directory, DNS, DHCP, Group Policy, and Linux user/group and permission management.
* Implement and oversee backup, recovery, and disaster recovery solutions for Windows and Linux environments.
* Apply OS patches and updates regularly; maintain administrative tools and utilities.
* Monitor system performance and provide statistics and reports.
* Develop and maintain installation, configuration, and maintenance procedures.
* Manage and verify security solutions, including firewalls, anti-virus/endpoint protection, and intrusion detection systems.
* Execute system upgrades, configuration changes, and file archival/purging as required.
* Collaborate with network, application, and database teams to ensure system reliability, availability, and scalability.
* Document system configurations, processes, and service records.
* Troubleshoot and resolve technical issues efficiently.
* Provide on-call after-hours support on a rotational basis.

Qualifications:

Clearance Level: Secret

Certifications:

* Must meet DoD 8570/8140 Information Assurance Technical (IAT-II) certification requirements
* Microsoft certifications such as Windows Server Hybrid Administrator Associate or Azure Administrator Associate
* AWS Cloud Practitioner

Experience:

* Proficiency in Windows Server (2016, 2019, 2022) and Linux administration (RHEL, Ubuntu, CentOS)
* Experience with Active Directory and Linux user/group management
* Knowledge of networking protocols and services (TCP/IP, DNS, DHCP, SMTP, HTTP/S)
* Experience with virtualization technologies (VMware, Hyper-V, KVM)
* Experience with scripting and automation (Power Shell, Bash, Python)
* Knowledge of system hardening and compliance to meet DoD security requirements
* Strong troubleshooting, documentation, and communication skills
* U.S. Citizenship required
* Position may require up to 25% travel
* OCONUS (Outside Continental United States) travel may be required

Preferred Qualifications
* Experience with cloud services (AWS, Azure) and hybrid environments
* Knowledge of database management (e.g., SQL Server, MySQL, Postgre

SQL)
* Experience with configuration management and automation tools (Ansible, SCCM, Puppet, Chef) Highly Desired
* Familiarity with ITIL processes and cybersecurity best practices
* Familiarity with Scaled Agile Framework (SAFe) v6.0 methodology Benefits at Sentar:
Our unique ownership model attracts top talent, giving employees the freedom to take initiative and drive meaningful improvements. In addition to cultivating a thriving and inclusive work environment, Sentar offers an extensive benefits package designed to support the well-being of employees and their families. Employee ownership is the foundation of our culture, promoting participation, teamwork, and accountability while ensuring long-term financial security and a commitment to excellence.

* Voluntary Medical, Dental, Vision, with Health Savings or Flexible Spending Plan options
* Voluntary Life, Critical Illness, Accident, and Long Term Care insurance options
* Group Term Life, Short-Term and Long-Term Disability is provided by Sentar to all qualifying employees
* Generous 401(k) match
* Competitive PTO plan that graduates quickly with years of service
* Other leave programs; holiday schedule along with bereavement, maternity, jury and military duty
* Mental health awareness programs
* Tuition reimbursement
* Professional development reimbursement
* Recognition and Awards programs If you are not ready to apply for this position, submit your resume here to join our talent community . We'll keep you updated occasionally on new job opportunities. Sentar is an Affirmative Action and Equal Opportunity Employer M/F/Vets/Persons with Disabilities Our culture is one of inclusivity and support. Sentar is proudly an Equal Opportunity and…