System Administrator

System Administrator

Role Summary

A System Administrator installs, configures, and maintains servers and operating systems — ensuring systems are secure, patched, monitored, and available for users and applications.

Core Responsibilities

• Install, configure, and maintain Linux/Windows servers
• Manage user accounts, groups, and permissions (LDAP, AD, IAM)
• Configure and maintain system services (web, mail, DNS, file servers)
• Automate routine tasks with scripts (Bash, PowerShell, Python)
• Apply security patches and OS hardening
• Manage storage, backups, and disaster recovery
• Monitor system health (CPU, memory, disk, network)
• Troubleshoot system issues and performance bottlenecks
• Document system configurations and procedures

Standard Workflow

1. Request/Issue — receive request or alert; classify and prioritize.
2. Assessment — check system logs, resource usage, service status.
3. Plan — determine fix or change; assess impact and rollback plan.
4. Change Window — schedule maintenance if needed; communicate to users.
5. Implementation — apply changes; verify with tests.
6. Verification — confirm services running, logs clean, monitoring green.
7. Documentation — update runbooks, CMDB, change log.

Technology Stack

Best Practices

• Automate everything repeatable — no manual ad-hoc fixes.
• Configuration management (Ansible/Puppet) for all server setup.
• Principle of least privilege for all accounts and services.
• Regular patching cadence — test on staging before production.
• Centralized logging (syslog, ELK) for troubleshooting.
• Document every server's purpose, owner, and config in CMDB.
• Immutable server pattern where possible (rebuild, don't patch).
• SSH key-based auth; disable password auth on production servers.

Anti-Patterns to Avoid

• Snowflake servers with undocumented manual configurations.
• Running services as root when unprivileged user suffices.
• No backup testing — verify restores periodically.
• Shared admin accounts — use individual accounts with sudo.
• Ignoring log rotation — disks fill up silently.
• Direct production changes without change management process.

References

• references/server-hardening-checklist.md — OS hardening guide
• references/backup-procedures.md — backup and restore procedures
• references/patching-policy.md — patching cadence and process

Expected Output Format

1. Configuration changes with Ansible playbook (or equivalent)
2. Before/after system metrics
3. Updated documentation/runbook
4. Change log entry