Title : Linux/UNIX System Administrator

Location: Johns Creek, GA 30097

Duration: 6+ months Contract to Hire

Top 3 Required Skills - 1) Linux 2) VMware 3) Kernel

• Detailed Job Description - see below

Overview

We are seeking a hands-on Linux / UNIX Systems Administrator to take full ownership of a 200+ Linux environment. This is a critical, execution-focused role.

This individual will stabilize, modernize, secure, and actively manage our Linux infrastructure, including systems supporting OS/400 (OS4) integrations for Rail operations.

What You Will Own

Infrastructure Operations

• Full lifecycle administration of ~222 Linux servers (production, QA, development)
• OS upgrades, patch management, and kernel updates
• Performance monitoring and system tuning (CPU, memory, disk I/O, network)
• User access management and authentication integrations (LDAP/AD)
• Backup validation and disaster recovery readiness

Security & Hardening

• Implement and maintain patching cadence across all Linux systems
• System hardening aligned to CIS/STIG best practices
• SELinux configuration and management
• Firewall configuration (iptables / firewalld)
• Support vulnerability remediation from scanning tools (Tenable, Qualys, etc.)
• Log monitoring and audit review

Incident Response & Production Stability

• Lead root cause analysis (RCA) for production incidents
• Participate in on-call support for critical issues
• Resolve Sev1/Sev2 outages and implement preventative controls
• Develop post-incident documentation and remediation plans

Modernization & Technical Debt Reduction

• Assess and remediate deprecated platform components
• Standardize system configurations
• Build documentation and operational runbooks
• Drive incremental infrastructure improvements

UNIX & OS/400 (OS4) Support

• Administer UNIX environments (AIX/Solaris experience preferred)
• Support integrations with IBM i (OS/400) systems supporting Rail operations
• Ensure proper update and lifecycle management across platforms
• Maintain cross-platform data and system dependencies

Technical Requirements

• 5+ years hands-on Linux system administration experience
• Strong experience with Red Hat, CentOS, Rocky, or Ubuntu
• Proven experience managing 100+ server environments
• Deep knowledge of:
  • Kernel tuning
  • LVM and file systems (ext4, XFS)
  • systemd, cron, process management
  • DNS, NTP, SSH configuration
  • TCP/IP fundamentals
  • NFS / Samba
• Experience supporting Linux in virtualized environments (VMware preferred)
• Familiarity with SAN/NAS storage
• Strong troubleshooting across OS, network, and storage layers
• Experience working within legacy environments undergoing modernization

Preferred Qualifications

• UNIX (AIX/Solaris) administration
• Experience with IBM i (OS/400)
• Infrastructure automation (Ansible, Puppet, Chef)
• Experience migrating legacy systems to modern platforms
• Security certifications (RHCSA, RHCE, Security+, etc.)
• Experience supporting rail, transportation, or industrial systems