Senior Linux & Windows Server Administrator (Oracle Cloud Infrastructure)

Company: DXC Technology Location: Riyadh, Saudi Arabia Business Unit: CES – ETP / Oracle Practice Experience: 8–10 years Role Summary DXC Technology is seeking a Senior Server OS Administrator with deep expertise in Oracle Linux, Red Hat Enterprise Linux (RHEL), and Windows Server across Oracle Cloud Infrastructure (OCI) and hybrid environments. You will manage the full operating system lifecycle, including provisioning, hardening, patching, performance tuning, automation, and compliance. The role supports the availability, security, and operational efficiency of enterprise compute workloads on OCI. Key Responsibilities OCI Compute and Instance Management • Provision and manage OCI compute instances, including virtual machines, Bare Metal, and Flex shapes, running Oracle Linux, RHEL, and Windows Server. • Configure instance metadata, cloud-init scripts, and custom images to support standardized deployments. • Build and maintain golden images and image pipelines for Linux and Windows Server on OCI. • Manage instance pools, autoscaling configurations, and capacity reservations. • Configure boot and block volumes, volume groups, backup policies, and cross-region replication. • Manage OCI Bastion and OS Management Hub for secure access and fleet management. Oracle Linux and RHEL Administration • Install, configure, and administer Oracle Linux 8/9 and RHEL 8/9 across OCI and on-premises environments. • Tune kernel parameters, sysctl settings, Huge Pages, and NUMA for enterprise workloads. • Manage packages and repositories using DNF/YUM, Unbreakable Linux Network (ULN), and Oracle Linux management tools. • Configure LVM, ext4, XFS, OCFS2, multipath, and iSCSI storage. • Administer systemd services, scheduled jobs, and system processes. • Use Oracle Ksplice for kernel patching where applicable. • Configure SELinux, firewalld, and iptables/nftables security controls. Windows Server Administration • Install, configure, and manage Windows Server 2019, 2022, and 2025 on OCI. • Administer Active Directory Domain Services, Group Policy, DNS, and DHCP in OCI-hosted and hybrid environments. • Manage Windows Server roles and features, including IIS, File Server, Print Server, WSUS, and Failover Clustering. • Configure Remote Desktop Services and Windows Admin Center. • Manage Storage Spaces, ReFS, NTFS permissions, and iSCSI initiators. • Oversee Windows patching and compliance using WSUS and relevant update management tools. • Apply Windows Defender, Windows Firewall, and security baselines. OS Patching and Lifecycle Management • Design and execute patching strategies across Oracle Linux, RHEL, and Windows Server using OCI OS Management Hub and other enterprise tools. • Manage patch schedules, compliance reporting, and exceptions across development, staging, and production environments. • Implement Oracle Ksplice and other appropriate methods to reduce downtime during patching. • Track operating system support lifecycles, end-of-life dates, and upgrade requirements. • Coordinate patching windows and rollback plans with application and database teams in line with change management processes. Security Hardening and Compliance • Apply CIS benchmarks across managed Linux and Windows Server instances. • Implement OS-level encryption using LUKS or BitLocker, with OCI Vault integration where required. • Harden SSH access and manage PAM, sudoers, certificates, and Linux authentication controls. • Manage local and domain-based access, privileged access, and service accounts. • Configure auditd, Windows Event Forwarding, and OCI Logging integration. • Support compliance activities through evidence collection, remediation, and operational controls. Networking and Connectivity • Configure OCI VNIC attachments, secondary VNICs, and OS-level network bonding or teaming. • Manage DNS resolution, NTP/Chrony, host-based routing, and network interfaces. • Align host firewall configurations with OCI Security Lists and network security groups. • Troubleshoot MTU, TCP, latency, and other OS-level connectivity issues across OCI networks. • Configure VPN clients and proxy settings for hybrid environments. Performance Monitoring and Tuning • Monitor CPU, memory, storage, and network performance using OCI monitoring services and native tools such as sar, vmstat, iostat, and perfmon. • Tune OS settings for database, middleware, and application workloads. • Configure OCI Compute metrics, alarms, and notifications for operating system health. • Conduct capacity planning and utilization analysis to guide scaling and right-sizing. • Integrate OS monitoring with tools such as Prometheus, Grafana, Datadog, or SCOM. Automation and Infrastructure as Code • Develop and maintain OS automation using Ansible, Terraform with the OCI provider, and OCI Resource Manager. • Build automated provisioning workflows using golden images, cloud-init, and post-provisioning configuration. • Automate user management, log rotation, disk cleanup, certificate renewals, and compliance checks using Bash, Python, or PowerShell. • Use configuration management tools to maintain consistent settings and identify configuration drift. • Support provisioning workflows integrated with CI/CD pipelines and IT service management tools. Operational Support and Leadership • Develop and maintain runbooks, standard operating procedures, and knowledge base articles. • Participate in on-call support, incident management, root cause analysis, and problem management. • Collaborate with cloud architects, DBA teams, middleware teams, and other stakeholders on platform decisions. • Mentor junior administrators and share technical knowledge across the team. Must-Have Experience • 8–10 years of server operating system administration across Oracle Linux, RHEL, and Windows Server. • Hands-on OCI Compute administration, including instances, custom images, and OS Management Hub. • Advanced Linux administration, including kernel tuning, LVM, filesystems, package management, systemd, SELinux, and firewalld. • Advanced Windows Server administration, including Active Directory, Group Policy, IIS, Failover Clustering, and security baselines. • Enterprise patching experience across mixed Linux and Windows environments. • OS automation using Ansible and at least one of Bash, Python, or PowerShell. • Terraform experience with the OCI provider for compute provisioning. • Working knowledge of OCI networking, including VCNs, subnets, NSGs, VNICs, and service gateways. • Experience applying CIS benchmarks and security hardening across Linux and Windows environments. Preferred Experience • Oracle Linux System Administrator, OCI Architect Associate, or OCI Operations Associate certification. • RHCSA or RHCE certification.

Must-Have Experience: 8–10 years of server operating system administration across Oracle Linux, RHEL, and Windows Server; Hands-on OCI Compute administration, including instances, custom images, and OS Management Hub; Advanced Linux administration (kernel tuning, LVM, filesystems, package management, systemd, SELinux, firewalld); Advanced Windows Server administration (Active Directory, Group Policy, IIS, Failover Clustering, security baselines); Enterprise patching experience across mixed Linux and Windows environments; OS automation using Ansible and at least one of Bash, Python, or PowerShell; Terraform experience with the OCI provider for compute provisioning; Working knowledge of OCI networking (VCNs, subnets, NSGs, VNICs, service gateways); Experience applying CIS benchmarks and security hardening across Linux and Windows.

Provision and manage OCI compute instances (VMs, Bare Metal, Flex shapes) running Oracle Linux, RHEL, and Windows Server; Build and maintain golden images and image pipelines; Manage instance pools, autoscaling, and capacity reservations; Configure storage (boot/ block volumes, LVM, ext4, XFS, OCFS2) and backups; Manage OCI Bastion and OS Management Hub; Install, configure, and administer Oracle Linux 8/9, RHEL 8/9, and Windows Server 2019/2022/2025; Administer Active Directory, GPOs, DNS, DHCP; Manage Windows roles/features (IIS, File Server, Print Server, WSUS, Failover Clustering); Patch and security hardening (Windows Defender, firewalls, CIS benchmarks); Design and execute OS patching strategies; Configure security controls (SELinux, firewalld, iptables/nftables); Monitor and tune OS performance; Automate provisioning and configurations with Ansible, Terraform (OCI provider), and OCI Resource Manager; Maintain runbooks, SOPs, and knowledge base; participate in on-call support, incident management, and cross-team collaboration; Mentor junior admins.