Job Description:
Role Summary
We are seeking a Senior Server OS Administrator with deep expertise in managing Oracle Linux, Red Hat Enterprise Linux (RHEL), and Windows Server operating systems across Oracle Cloud Infrastructure (OCI) and hybrid environments. This role is responsible for OS provisioning, hardening, patching, performance tuning, automation, and compliance ensuring enterprise compute workloads operate with maximum availability, security, and operational efficiency on OCI.
Key Responsibilities
OCI Compute & Instance Management
- Provision and manage OCI compute instances (VM, Bare Metal, Flex shapes) across Oracle Linux, RHEL, and Windows Server platforms.
- Configure and manage OCI instance metadata, cloud-init scripts, and custom images for standardized OS deployments.
- Build and maintain golden images (custom images, image pipelines) for Oracle Linux, RHEL, and Windows Server on OCI.
- Manage instance pools, autoscaling configurations, and capacity reservations for dynamic workload demands.
- Configure OCI boot/block volumes, volume groups, backup policies, and cross-region replication for OS-level storage.
- Manage OCI Bastion service and OS Management Hub for secure access and fleet management.
Oracle Linux & RHEL Administration
- Install, configure, and manage Oracle Linux (8.x/9.x) and RHEL (8.x/9.x) across OCI and on-premises environments.
- Administer kernel parameters, sysctl tuning, Huge Pages, NUMA, and kernel-level performance optimization.
- Manage package management using DNF/YUM, ULN (Unbreakable Linux Network), and Oracle Linux Manager/Spacewalk.
- Configure and maintain LVM, filesystems (ext4, XFS, OCFS2), multipath, and iSCSI storage at the OS layer.
- Administer systemd services, cron scheduling, and process management.
- Manage Oracle Ksplice for zero-downtime kernel patching on Oracle Linux.
- Configure SELinux policies, firewalld rules, and iptables/nftables for OS-level security.
Windows Server Administration
- Install, configure, and manage Windows Server (2019/2022/2025) on OCI compute instances.
- Administer Active Directory Domain Services (AD DS), Group Policy Objects (GPOs), DNS, and DHCP in OCI-hosted or hybrid-connected Windows environments.
- Manage Windows Server roles and features: IIS, File Server, Print Server, WSUS, and Failover Clustering.
- Configure and manage Windows Remote Desktop Services (RDS) and Windows Admin Center.
- Administer Windows storage: Storage Spaces, ReFS, NTFS permissions, and iSCSI initiators.
- Manage Windows Update for Business, WSUS, and patch compliance across OCI-hosted Windows fleets.
- Configure Windows Defender, Windows Firewall with Advanced Security, and security baselines.
OS Patching & Lifecycle Management
- Design and execute OS patching strategies across Oracle Linux, RHEL, and Windows Server using OCI OS Management Hub.
- Manage patching schedules, patch compliance reporting, and exception handling across development, staging, and production environments.
- Implement zero-downtime patching workflows using Oracle Ksplice (Linux) and live patching techniques.
- Maintain OS lifecycle compliance track end-of-life, extended support, and upgrade paths across all supported OS versions.
- Coordinate patching windows with application and database teams, ensuring rollback readiness and change management alignment.
Security Hardening & Compliance
- Apply CIS benchmarks for Oracle Linux, RHEL, and Windows Server across all managed instances.
- Implement OS-level encryption: LUKS (Linux), BitLocker (Windows), and OCI Vault integration for key management.
- Configure and manage SSH hardening, PAM modules, sudoers policies, and certificate-based authentication (Linux).
- Manage local and domain-based access controls, privilege escalation policies, and service account governance.
- Implement audit logging using auditd (Linux), Windows Event Forwarding (WEF), and OCI Logging integration.
- Support compliance frameworks (SOC2, ISO 27001, PCI-DSS, CIS) through evidence collection and remediation at the OS layer.
Networking & OS-Level Connectivity
- Configure OCI VNIC attachments, secondary VNICs, and OS-level network interface bonding/teaming.
- Manage OS-level DNS resolution, NTP/Chrony configuration, and host-based routing on OCI instances.
- Configure OS-level firewall rules aligned with OCI Security Lists and NSGs.
- Troubleshoot OS-level network issues including MTU, TCP tuning, and latency across OCI VCN topologies.
- Configure and manage VPN client connectivity and proxy settings for hybrid environments.
Performance Monitoring & Tuning
- Monitor OS performance metrics (CPU, memory, I/O, network) using OCI Monitoring Agent, OS Management Hub, and native OS tools (sar, vmstat, iostat, perfmon).
- Tune OS-level parameters for database, middleware, and application workloads including shared memory, semaphores, file descriptors, and kernel limits.
- Implement and manage OCI Compute metrics, custom alarms, and notifications for OS-level health monitoring.
- Conduct capacity planning and resource utilization analysis to inform scaling and right-sizing decisions.
- Integrate with enterprise monitoring stacks (Prometheus, Grafana, Datadog, SCOM) for unified observability.
Automation & Infrastructure as Code
- Develop and maintain OS automation using Ansible, Terraform (OCI provider), and OCI Resource Manager.
- Build automated OS provisioning pipelines golden image creation, cloud-init bootstrapping, and post-provisioning configuration.
- Automate routine OS tasks: user management, log rotation, disk cleanup, certificate renewals, and compliance checks using Bash, Python, and PowerShell.
- Implement configuration management and drift detection using Ansible, Puppet, or Chef across managed fleets.
- Build self-service OS provisioning workflows integrated with CI/CD pipelines and ServiceNow ITSM.
General
- Develop and maintain operational runbooks, SOPs, and knowledge base articles for OS administration procedures.
- Participate in on-call rotations, incident management, root cause analysis, and problem management.
- Collaborate with cloud architects, DBA teams, middleware teams, and client stakeholders on platform decisions.
- Mentor junior OS administrators and contribute to knowledge sharing within the practice.
Required Skills & Experience
- 8–10 years of progressive experience in server OS administration with hands-on expertise across Oracle Linux, RHEL, and Windows Server.
- Strong experience managing OS workloads on OCI (Compute instances, custom images, OS Management Hub).
- Expert-level knowledge of Linux administration: kernel tuning, LVM, filesystems, package management, systemd, SELinux, and firewalld.
- Expert-level knowledge of Windows Server administration: Active Directory, GPO, IIS, Failover Clustering, and Windows security baselines.
- Proven experience designing and executing enterprise OS patching strategies across mixed Linux/Windows fleets.
- Strong proficiency in OS automation using Ansible and at least one scripting language: Bash, Python, or PowerShell.
- Hands-on experience with Infrastructure as Code (Terraform with OCI provider) for compute provisioning.
- Solid understanding of OCI networking: VCNs, subnets, NSGs, VNICs, and service gateways as they relate to OS-level configuration.
- Experience applying CIS benchmarks and security hardening across Linux and Windows platforms.
- Excellent communication skills with the ability to produce clear operational documentation and engage with cross-functional teams.
Preferred Skills
- Oracle certifications: Oracle Linux System Administrator (OCA/OCP), OCI Architect Associate, OCI Operations Associate.
- Red Hat certifications: RHCSA, RHCE.
- Microsoft certifications: Windows Server Hybrid Administrator Associate (AZ-800/AZ-801).
- Experience with Oracle Ksplice for zero-downtime kernel patching.
- Familiarity with OCI OS Management Hub and Oracle Linux Manager at scale.
- Experience with configuration management tools: Puppet, Chef, or SaltStack.
- Knowledge of container runtimes (Podman, Docker) and container host OS management on OCI.
- Experience with enterprise monitoring: Prometheus, Grafana, Datadog, SCOM, or OEM.
- Familiarity with ITSM integration (ServiceNow) for automated provisioning and change management.
- ITIL Foundation or equivalent service management awareness.
- Experience working in managed services or consulting delivery environments.
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