“We Train, You Succeed: Trusted by Thousands for Training & Placement”. Know more!

Call us @ 9666019191

HomeAwsLinux Interview Questions for Cloud and Devops engineers

Linux Interview Questions for Cloud and Devops engineers

Here are some key Linux interview questions tailored for an AWS and DevOps engineer with experience:

Basic Linux Commands and Concepts:

  1. What is the use of the chmod, chown, and chgrp commands?
    1. Follow-up: How would you give read and write permissions to a user?
  2. How do you check memory and CPU usage on a Linux system?
    1. Commands: top, htop, vmstat, free, sar.
  3. How would you search for a pattern in a file using grep?
    1. Follow-up: How would you search recursively through directories for a pattern?
  4. What is the purpose of the cron command?
    1. Follow-up: Explain how to schedule a cron job and how to check if it’s running.
  5. Explain how to monitor disk usage and free space on a Linux system.
    1. Commands: df, du.
  6. What does the ps command do, and how would you find a specific process using it?
    1. Follow-up: How would you kill a process using the process ID?

Advanced Linux Concepts:

  • Explain how you can manage services in Linux (start, stop, restart).
    • Use of systemctl, service, init.d for various distributions.
  • What are runlevels in Linux?
    • Follow-up: What is the difference between runlevel 3 and runlevel 5?
  • What is the difference between a hard link and a soft (symbolic) link?
    • Follow-up: How would you create both types of links?
  • Explain the Linux boot process.
    • Follow-up: What role does grub play in the boot process?
  • How do you find large files in a directory?
    • Command: find / -type f -size +100M

Networking and Security:

  1. How do you check the network configuration on a Linux system?
    1. Command: ifconfig, ip addr, ip route.
  2. How would you configure a static IP address on a Linux server?
  3. Explain how to use iptables to block or allow traffic.
    1. Follow-up: How does ufw differ from iptables?
  4. What is SSH, and how do you secure it?
    1. Follow-up: How do you set up SSH key-based authentication?
  5. How do you set up a firewall in Linux?
    1. Commands like firewalld, iptables, and ufw.

AWS-Specific Linux Operations:

  1. How would you automate the setup of a Linux EC2 instance in AWS using shell scripts?
  2. Explain how you would set up and mount an EBS volume on an EC2 instance.
    1. Commands: lsblk, mount, fdisk, mkfs.
  3. How would you set up auto-scaling and load balancing for a Linux-based web server in AWS?
  4. How do you use the AWS CLI to manage EC2 instances?
    1. Follow-up: How would you automate routine tasks (e.g., start, stop EC2) using shell scripts and AWS CLI?

DevOps and Automation:

  • Explain the use of configuration management tools like Ansible or Puppet in managing Linux systems.
    • Follow-up: How would you use Ansible to install packages on multiple Linux servers?
  • What are the best practices for logging and monitoring Linux servers in a DevOps environment?
    • Tools like Nagios, Prometheus, Grafana, AWS CloudWatch.
  • How would you set up continuous integration and deployment (CI/CD) pipelines in a Linux environment using Jenkins?
  • How would you automate the deployment of an application on Linux servers using Docker?
  • Explain the steps involved in setting up a Kubernetes cluster on Linux.
  • How do you use cron to automate regular backups in a Linux environment?
  • How do you ensure the security and compliance of Linux-based systems in AWS?
    • Follow-up: Tools like AWS Security Groups, IAM roles, VPC, and auditing tools like AWS CloudTrail.

System Troubleshooting and Optimization:

  • How do you troubleshoot a Linux server that is running slow?
    • Commands: top, iostat, vmstat, netstat, checking logs.
  • How would you recover a corrupted Linux filesystem?
    • Commands like fsck, e2fsck.
  • Explain how to deal with kernel panics or system crashes in Linux.

These questions will help gauge your Linux proficiency in the context of AWS and DevOps environments, focusing on automation, networking, security, and troubleshooting skills.

Here are advanced Linux interview questions tailored for Cloud and DevOps engineers with experience, focusing on real-world scenarios, performance tuning, and automation in cloud environments:

System and Kernel Management:

  1. Explain the role of the kernel in Linux. How do you view kernel messages?
    1. Use of dmesg, /var/log/messages.
  2. How do you upgrade the Linux kernel in a production environment?
    1. Follow-up: What are the best practices for upgrading the kernel in a cloud-based system?
  3. What is the difference between monolithic and microkernel architecture?
    1. Follow-up: Why is Linux considered a monolithic kernel?
  4. How do you tune kernel parameters for networking using sysctl?
    1. Example: Tuning parameters like net.ipv4.tcp_fin_timeout, fs.file-max.
  5. Explain the concept of kernel modules. How do you load, unload, and check modules?
    1. Use of modprobe, lsmod, rmmod.

File System and Storage:

  • How do you handle a situation where a file system is full but no large files are visible?
    • Concepts: Hidden space, orphaned inodes, lsof, du.
  • Explain LVM (Logical Volume Manager) and its importance in Linux.
    • Follow-up: How do you resize a logical volume in a running system?
  • What is the difference between ext4, xfs, and btrfs file systems?
    • Follow-up: When would you use one over the other in a cloud environment?
  • How do you recover from a corrupted or unmountable file system on a Linux server?
    • Tools: fsck, e2fsck, debugfs.
  • What is the purpose of the swap space? How do you optimize swap usage on a Linux server?

Networking and Security:

  1. Explain how you would set up VLANs (Virtual LANs) in Linux.
    1. Use of vconfig, ip link add link.
  2. What are Linux network namespaces? How are they used in containerization and cloud networking?
  3. How do you optimize network performance in Linux (e.g., TCP tuning)?
    1. Concepts: TCP window scaling, congestion control algorithms, net.ipv4.tcp_rmem, ethtool.
  4. What are the key differences between iptables, nftables, and firewalld?
    1. Follow-up: How do you migrate from iptables to nftables?
  5. How do you use tcpdump to debug network issues?
    1. Follow-up: Provide examples of common use cases for tcpdump.
  6. Explain SELinux and its role in securing Linux systems. How do you troubleshoot SELinux issues?
    1. Commands: getenforce, setenforce, audit2allow.

Automation and Scripting:

  1. How would you automate the configuration of multiple Linux servers using Ansible?
    1. Follow-up: How do you handle dynamic inventory in cloud environments like AWS and Azure?
  2. Explain the concept of a shebang in shell scripts. Why is it important in script execution?
  3. How do you use cron to schedule jobs? How do you handle job failures and logging for cron jobs?
    1. Follow-up: Compare cron with systemd timers for scheduling tasks.
  4. What is the difference between synchronous and asynchronous execution in shell scripting?
    1. Commands: &, nohup, wait, disown.
  5. How do you optimize a shell script for better performance?
    1. Techniques: Avoiding forks, using built-in commands, parallel execution with xargs.

Cloud Integration:

  • How do you automate the creation of EC2 instances in AWS using Linux shell scripts?
    • Follow-up: How do you ensure that the EC2 instance is fully configured after booting (cloud-init, user data)?
  • Explain how you would implement centralized logging for a fleet of Linux instances in a cloud environment.
    • Tools: rsyslog, syslog-ng, AWS CloudWatch, ELK stack.
  • How do you handle dynamic DNS updates for Linux servers in cloud environments?
    • Use of Route 53 in AWS, Azure DNS, or external DNS services.

Containers and Orchestration:

  • What are Linux control groups (cgroups), and how are they used in Docker or Kubernetes?
    • Follow-up: How do you manage resource limits using cgroups?
  • Explain the concept of Linux namespaces and how they relate to containers.
    • Follow-up: How do namespaces ensure isolation in Docker?
  • How would you troubleshoot issues with Docker containers in a Linux environment?
    • Commands: docker logs, docker exec, strace, nsenter.
  • What is the role of overlay and btrfs storage drivers in Docker on Linux?
    • Follow-up: How do you optimize Docker storage performance?

System Performance and Troubleshooting:

  • How do you troubleshoot high CPU usage on a Linux server?
    • Tools: top, htop, sar, perf, iostat, strace.
  • What is strace, and how do you use it to debug a slow or failing process?
    • Follow-up: How do you use strace to trace system calls?
  • Explain how to diagnose and fix I/O bottlenecks in Linux.
    • Tools: iostat, iotop, dstat.
  • What is OOM Killer (Out Of Memory Killer), and how do you configure it to handle memory overcommitment in Linux?
    • Concepts: Overcommit ratio, oom_adj, sysctl vm.overcommit_memory.
  • How do you handle a disk full issue on a Linux system without downtime?
    • Techniques: File compression, moving data, lsof to identify open files, clearing unnecessary logs.
  • How do you identify and resolve deadlocks in Linux?

Virtualization and Cloud Integration:

  • Explain how KVM (Kernel-based Virtual Machine) works on Linux. How do you use it in cloud environments?
  • How do you optimize Linux servers running in virtualized environments for performance (e.g., EC2, Azure VMs)?
  • What is the difference between paravirtualization and hardware-assisted virtualization? How does it affect performance on cloud platforms?

Monitoring and Observability:

  • How would you monitor and scale Linux systems in a cloud environment (e.g., AWS CloudWatch, Prometheus)?
  • Explain how you use prometheus-node-exporter to gather system metrics from Linux instances.
    • Follow-up: How do you integrate this with Grafana for visualizing metrics?
  • How do you set up and configure audit logs in Linux to track user activity and system changes?
    • Tools: auditd, /var/log/auth.log, ausearch, auditctl.

Security and Hardening:

  • How do you secure a Linux system running in a public cloud (e.g., AWS, Azure)?
    • Concepts: VPC security, firewalls, IAM roles, least privilege, patch management.
  • How do you configure AppArmor on a Linux system, and how does it differ from SELinux?
  • Explain how you would perform vulnerability scanning on a fleet of Linux servers in a DevOps environment.
    • Tools: OpenVAS, ClamAV, AWS Inspector, Lynis.

These advanced questions focus on real-world scenarios that a Cloud and DevOps Engineer with experience might encounter. They cover a wide range of topics, from system optimization and network tuning to cloud integration and container orchestration.

Need a job in Cloud and Devops call +91-9666019191

Leave A Reply

Your email address will not be published. Required fields are marked *

You May Also Like

Building a career in AWS, Azure, and DevOps requires a blend of technical skills, certifications, practical experience, and strategic learning....
AWS interview questions specifically focused on AWS Lambda, API Gateway, Step Functions, and SQS (Simple Queue Service): AWS Lambda API...
The roles of DevOps Engineer and Site Reliability Engineer (SRE) are closely related, but they have distinct focuses and responsibilities....
×

Hello!

Click one of our contacts below to chat on WhatsApp

×