Lead System Administrator

POSITION OVERVIEW We are seeking a highly experienced Red Hat Linux Administrator with strong expertise in SQL database administration and Ansible automation to join our enterprise infrastructure team. This role is responsible for the reliable operation, security, performance, and continuous improvement of our Linux server estate spanning on-premises RHEL environments, hybrid cloud deployments, and database platforms. The ideal candidate combines deep systems administration skills with the automation mindset of a modern DevOps practitioner, leveraging Ansible to eliminate manual toil, enforce configuration consistency, and accelerate delivery of infrastructure at scale. RHCSA/RHCE certification is essential; experience with Red Hat Ansible Automation Platform is highly valued. THREE PILLARS OF THE ROLE Red Hat Linux Administration RHEL 8 / 9 system management Performance tuning & optimisation Security hardening & SELinux Storage, LVM & filesystem mgmt Patch & lifecycle management SQL & Database Administration MySQL & PostgreSQL admin Query writing & optimisation Backup, restore & replication Schema design & data integrity Performance monitoring & tuning Ansible Automation Playbook & role development Ansible Automation Platform Infrastructure-as-Code (IaC) Configuration drift remediation CI/CD pipeline integration HOW SUCCESS IS MEASURED 99.9% Linux server uptime SLA Mean Time to Recover (MTTR) 100% Patch compliance within window > 80% Infra tasks automated via Ansible KEY RESPONSIBILITIES Red Hat Enterprise Linux Administration Install, configure, and maintain RHEL 8 / 9 systems across physical, virtual (VMware / KVM), and cloud (AWS / Azure) environments at enterprise scale. Manage system performance tuning using tuned profiles, sysctl parameters, CPU/memory/IO analysis with tools such as sar, top, vmstat, iostat, and perf. Administer storage infrastructure including LVM (logical volume management), XFS/ext4 filesystems, NFS/CIFS mounts, multipath I/O, and disk quota management. Configure and maintain high-availability clustering using Pacemaker / Corosync and Red Hat Cluster Suite for mission-critical workloads. Own the Linux patching lifecycle planning, scheduling, testing, and applying errata using Red Hat Satellite / RHSM and subscription management. Implement and maintain user and group management, PAM authentication, LDAP/AD integration (SSSD, Kerberos, Winbind), and sudo policy governance. Manage and troubleshoot systemd services, journald logging, rsyslog, logrotate, and centralized log shipping to SIEM platforms. Security Hardening & Compliance Implement and enforce SELinux policies (targeted / enforcing mode), manage file contexts, port labels, and audit rule sets for all managed systems. Configure and maintain firewalld zones, rich rules, and iptables as required to restrict network access per security zoning policies. Apply CIS Red Hat Linux Benchmarks, DISA STIG hardening guidelines, and internal security baselines across the server estate via Ansible. Manage OpenSSL certificates, SSH key governance, PKI integration, and secrets management (HashiCorp Vault / Red Hat Secrets Manager). Conduct regular vulnerability scanning (OpenSCAP, Nessus, Qualys), interpret scan results, and drive remediation within agreed SLAs. Maintain system audit trails with auditd, generate compliance reports, and support internal and external security audit processes. Ansible Automation & Infrastructure-as-Code Design, develop, and maintain Ansible playbooks, roles, and collections for OS provisioning, configuration management, application deployment, and patching. Build and manage Ansible Automation Platform (AAP / AWX) job templates, inventories, credentials, workflows, and RBAC policies. Implement idempotent, reusable Ansible roles using best practices: variable precedence, handlers, tags, conditionals, and Jinja2 templating. Develop dynamic inventories integrating with VMware vCenter, AWS EC2, Azure Resource Manager, and Red Hat Satellite as authoritative sources of truth. Integrate Ansible with CI/CD pipelines (Jenkins, GitLab CI, GitHub Actions) for automated infrastructure testing and deployment workflows. Enforce configuration drift detection and remediation using scheduled Ansible playbook runs and compliance-as-code frameworks. Maintain Ansible code in Git repositories with structured branching strategies, peer code review, and automated linting (ansible-lint, yamllint). SQL & Database Administration Install, configure, and administer MySQL and PostgreSQL database instances on RHEL, including multi-instance setups, replication, and failover configurations. Write, review, and optimise complex SQL queries, stored procedures, functions, and triggers to support application and reporting requirements. Design and maintain database schemas, indexes, partitioning strategies, and data archival policies aligned to performance and retention objectives. Implement and manage database backup strategies logical (mysqldump, pg_dump) and physical (Percona XtraBackup, Barman) with verified restore testing. Monitor database performance using slow query logs, EXPLAIN plans, pg_stat views, and Performance Schema; resolve bottlenecks proactively. Manage database security including user access control, role-based permissions, SSL/TLS connections, and database audit logging. Automate routine DBA tasks (backups, index rebuilds, statistics updates, space monitoring) via Ansible playbooks and cron-driven shell scripts. Scripting, Monitoring & Automation Write and maintain Bash and Python shell scripts for system administration tasks, log parsing, health checks, and custom monitoring integrations. Deploy and manage infrastructure monitoring using tools such as Zabbix, Nagios, Prometheus + Grafana, or Red Hat Insights for real-time system visibility. Configure alerting thresholds, escalation paths, and on-call runbooks for Linux system events, database alerts, and Ansible job failures. Manage cron and systemd timer-based scheduled tasks for maintenance windows, backups, reporting, and housekeeping automation. Contribute to infrastructure documentation including SOPs, runbooks, build guides, and post-incident reports in Confluence or equivalent platforms. Cloud, Virtualisation & Hybrid Infrastructure Administer RHEL workloads on AWS (EC2, EBS, S3 integration) and Azure (Virtual Machines, Managed Disks) using cloud-native CLI and IaC tools. Manage KVM / QEMU hypervisor environments and libvirt-based virtual machine lifecycle including cloning, snapshotting, and resource allocation. Integrate Red Hat Satellite for content lifecycle management, host registration, activation keys, and automated provisioning of new RHEL instances. Participate in capacity planning exercises, cloud cost optimisation reviews, and infrastructure right-sizing initiatives for Linux workloads. Collaboration, Change & Documentation Participate in the change advisory board (CAB) process, preparing RFC documentation and risk assessments for all significant Linux infrastructure changes. Collaborate with application, security, network, and database teams to deliver integrated infrastructure solutions and resolve cross-team incidents. Provide Tier 3 escalation support for Linux system issues, leading diagnosis, resolution, and post-incident root-cause analysis. Mentor junior Linux administrators, conduct knowledge-sharing sessions, and contribute to internal technical training programmes. REQUIRED QUALIFICATIONS Education & Experience Bachelors degree in Computer Science, Information Technology, Systems Engineering, or a related technical discipline (or equivalent hands-on experience). 5-10 years of Linux system administration experience with a minimum of 3 years on Red Hat Enterprise Linux in production enterprise environments. Demonstrable hands-on experience writing and maintaining Ansible playbooks and managing infrastructure via Ansible Automation Platform or AWX. Solid SQL skills across MySQL and/or PostgreSQL query development, performance tuning, replication setup, and backup/recovery operations. Proven experience with Bash / Python scripting for automation, monitoring integration, and operational task management. Certifications 000 Certification Issuing Body Status SQL & Database Administration MySQL & PostgreSQL admin Query writing & optimisation Backup, restore & replication Schema design & data integrity Performance monitoring & tuning Red Hat Mandatory Red Hat Certified Engineer (RHCE - EX294 / Ansible) Red Hat Mandatory Red Hat Certified Specialist in Ansible Automation (EX407) Red Hat Preferred Red Hat Certified Architect (RHCA) Ansible Automation Playbook & role development Ansible Automation Platform Infrastructure-as-Code (IaC) Configuration drift remediation CI/CD pipeline integration Advantageous Oracle MySQL Database Administrator (1Z0-908) Oracle Preferred PostgreSQL Associate Certification (PGCA) The PostgreSQL Association Preferred AWS Certified SysOps Administrator - Associate Amazon Web Services 99.9% Linux server uptime SLA HashiCorp Certified: Vault Associate HashiCorp Advantageous TECHNICAL SKILLS 40 99.9% Linux server uptime SLA Security & Hardening SELinux (enforcing / targeted) Firewalld / iptables / nftables OpenSCAP / DISA STIG / CIS PAM / SSSD / Kerberos / LDAP SSH key management / PKI HashiCorp Vault / secrets mgmt Ansible Automation Playbooks / Roles / Collections Ansible Automation Platform (AAP) Dynamic inventory plugins Jinja2 templating ansible-lint / molecule testing Ansible Galaxy / private hub SQL & Databases MySQL 8.x admin & replication PostgreSQL 15/16 admin Query optimisation / EXPLAIN Backup: XtraBackup / Barman Replication: GTID / Streaming pgBouncer / ProxySQL pooling Scripting & Automation Bash scripting (advanced) Python 3.x (sysadmin scripts) Cron / systemd timers AWK / sed / grep / jq Git / version control Makefile / task runners Cloud & Hybrid Infra AWS EC2 / EBS / S3 / IAM Azure VMs / Managed Disks Terraform (infra provisioning) Cloud-init / user-data scripts AWS CLI / Azure CLI Cloud cost tagging & governance Mean Time to Recover (MTTR) Monitoring & Observability Prometheus + Grafana Zabbix / Nagios / PRTG Red Hat Insights ELK Stack (log analytics) Datadog / Dynatrace agents PagerDuty / OpsGenie alerting Collaboration & ITSM JIRA / Confluence ServiceNow ITSM integration Git branching (GitFlow) Agile / Scrum delivery Change management (CAB) Runbook & SOP authoring PREFERRED QUALIFICATIONS Experience with Red Hat OpenShift Container Platform (OCP) and managing containerised workloads on RHEL infrastructure. Hands-on knowledge of Terraform for provisioning RHEL infrastructure across AWS and Azure in conjunction with Ansible for post-provisioning configuration. Familiarity with MS SQL Server administration on Linux (SQL Server on RHEL) for hybrid Windows/Linux database environments. Experience with Percona XtraDB Cluster or Galera Cluster for multi-master MySQL high-availability architectures. Exposure to Red Hat Insights for predictive analytics, drift detection, and vulnerability prioritisation across the RHEL estate. Knowledge of identity management platforms such as Red Hat IdM (FreeIPA) or CyberArk PAM for privileged access control.