The short answer: system administrator interviews test whether you can keep systems running, secure and recoverable: operating systems (Linux and Windows), identity and permissions (often Active Directory), core network services (DNS, DHCP), backups and disaster recovery, patching and security, monitoring, and scripting to automate routine work. Expect troubleshooting scenarios (“A user can’t reach a shared drive…”) and questions about outages you handled. Below are the common questions with short answers.
What the job involves
The U.S. Bureau of Labor Statistics says network and computer systems administrators “install, configure, and maintain organizations’ computer networks and systems,” including security, performance, user accounts and permissions, training users, and diagnosing problems. The median pay was $99,130 in May 2025.
Operating systems
“How do you check what’s using CPU or memory on a Linux server?”
top or htop for live usage, free -h for memory, ps aux --sort=-%cpu to list heavy processes, and df -h and du for disk space.
“How do you find why a Linux service won’t start?”
systemctl status <service> and journalctl -u <service> for logs, check the configuration file, permissions, and whether the port is already in use.
“How do you manage permissions on Linux?”
Users and groups with chmod, chown and, where needed, access control lists. Grant the least privilege needed and use sudo rather than shared root access.
Windows and Active Directory
“What is Active Directory?”
Microsoft’s directory service for managing users, computers and groups in a domain, with authentication and Group Policy for central configuration.
“What is Group Policy used for?”
Applying settings centrally, such as password rules, software installation, drive mappings and security settings.
“A user is locked out repeatedly. What do you check?”
Saved credentials on other devices (phones, mapped drives, services) using an old password, and the lockout source in the security logs.
Networking
“What do DNS and DHCP do?”
DNS translates names into IP addresses; DHCP assigns IP addresses and network settings to devices automatically.
“A user can’t reach a website. How do you troubleshoot?”
Work up the layers: physical connection, IP address (ipconfig or ip addr), default gateway (ping), DNS resolution (nslookup), the route (traceroute), then the application or proxy.
Backups and recovery
“What’s your backup strategy?”
Regular automated backups following the 3-2-1 approach (three copies, two types of media, one off-site), defined recovery point and recovery time objectives, and above all regular restore tests.
“Tell me about a time you restored from backup.”
Describe what failed, how you restored, how long it took, and what you changed afterward.
Security and patching
“How do you manage patching?”
A regular schedule, testing patches on a small group first, prioritizing critical security updates, maintenance windows, and a rollback plan.
“How do you secure a server?”
Remove unused services, apply updates, enforce strong authentication (keys, MFA), restrict access with firewalls and least privilege, monitor logs, and keep backups.
Monitoring and automation
“What do you monitor, and how?”
Availability, CPU, memory, disk, network, service health and logs, with alerts tied to action. Name the tools you’ve used.
“What have you automated?”
Give a real example: a PowerShell or Bash script for user onboarding, log cleanup or backups, with the time it saved.
Scenario and behavioral questions
- “The file server is down during business hours. What do you do?” Communicate early, assess impact, restore service (failover or restore), find the root cause, and document.
- “Tell me about the worst outage you handled.” See solving a complex problem.
- “How do you handle a frustrated user?” See difficult customer questions.
- “How do you prioritize several urgent tickets?” See how do you handle stress.
See also our networking interview questions and what to wear to an interview.
Frequently asked questions
What questions are asked in a system administrator interview?
How do I answer a troubleshooting question in a sysadmin interview?
What is the 3-2-1 backup rule?
How much do system administrators earn?
What scripting languages should a sysadmin know?
Sources
- U.S. Bureau of Labor Statistics, Occupational Outlook Handbook, Network and Computer Systems Administrators. Read on 1 October 2026.
