Azure Cloud Virtual Machine

Azure Cloud

Azure VM Tasks & Common Interview Topics

1. Azure VM Basics

  • Creating VMs: Understand the basics of creating and configuring VMs using both the Azure portal and Azure CLI. You should know different VM sizes, disk types, and pricing tiers.
  • Start/Stop/Deallocate: Commands to start, stop, and deallocate VMs, and understanding the difference between stopping and deallocating a VM.
  • Resizing a VM: Know how to resize a VM and the impact it has on the underlying infrastructure.

2. VM Networking

  • Public vs Private IP Addresses: Configure and assign static/dynamic public and private IPs to Azure VMs.
  • NSG (Network Security Groups): Configure NSGs to control inbound and outbound traffic for VMs.
  • Load Balancing: Understand how to set up and use Azure Load Balancers for distributing traffic to multiple VMs.
  • VNET and Subnets: Networking for VMs, including Virtual Networks (VNET), subnets, and peering.

3. Disks and Storage

  • Managed vs Unmanaged Disks: Know the difference and implications on performance and cost.
  • Attaching and Detaching Disks: Learn how to attach additional data disks to a VM and detach them when not needed.
  • Disk Performance Tiers: Differences between Standard, Premium, and Ultra disks, and when to use each.

4. VM Images and Snapshots

  • Creating Custom VM Images: Capture a VM as an image and reuse it to deploy new VMs with pre-configured environments.
  • Snapshots: Creating and restoring from snapshots for backups.

5. Automation and Scaling

  • Azure VM Scale Sets: Use VM Scale Sets for auto-scaling applications across multiple VMs.
  • Automation: Use ARM Templates, Terraform, or Azure CLI to automate VM provisioning.
  • Azure DevOps Pipelines: Automate VM creation and deployment as part of a CI/CD pipeline.

6. Azure VM Security

  • Azure Bastion: Secure RDP/SSH access to VMs without exposing public IPs.
  • Disk Encryption: Configure Azure Disk Encryption to secure data at rest.
  • Managed Identities: Implement MSI for secure access to Azure resources without credentials.
  • SSH Key Management: Generate and use SSH keys for Linux VM access, as well as passwordless access for Windows VMs.

7. Backup and Disaster Recovery

  • Azure Backup: Set up Azure Backup for VM snapshots and restoring VMs in case of failure.
  • Azure Site Recovery (ASR): Replicate and failover VMs for disaster recovery scenarios.

8. Troubleshooting

  • Diagnosing VM Issues: Diagnose and troubleshoot VMs that fail to start or have performance issues (check logs, resource utilization, and network connectivity).
  • Monitoring and Alerts: Set up monitoring using Azure Monitor and create alerts based on VM metrics like CPU usage, memory consumption, or disk IOPS.

9. Cost Management

  • Azure Reserved Instances: Understand the concept of reserved VM instances to save on long-term costs.
  • Spot VMs: Use Azure Spot VMs for cost-effective workloads and understand their limitations.
  • VM Pricing: Estimate costs and optimize VMs for pricing based on workload needs.

10. OS-Specific Knowledge

  • Windows VMs: Setting up RDP, enabling WinRM for remote management, configuring updates, and managing licensing.
  • Linux VMs: SSH access, handling Linux kernel updates, and automating tasks with scripts.

Common Interview Questions

  1. How would you create a virtual machine in Azure and configure it with specific VM size and OS?

    • Testing knowledge on Azure CLI, ARM Templates, or Terraform to automate VM creation.

  2. What is the difference between deallocating and stopping a VM?

    • Stopping still incurs costs for resources, while deallocating releases hardware and stops billing for the VM.

  3. How do you securely connect to a VM in Azure without exposing public IPs?

    • Usage of Azure Bastion, Just-in-Time (JIT) VM access, or private endpoint configurations.

  4. Explain Azure VM scale sets and how you would configure autoscaling.

    • Understand scaling rules, thresholds, and VM image configuration.

  5. What are managed identities, and how would you use them in Azure VMs?

    • Assigning VMs identity in Azure AD and granting access to Azure resources without credentials.

  6. How would you troubleshoot a VM that is not responding or has network connectivity issues?

    • Diagnose network security groups, VNET configurations, or use Azure Serial Console for troubleshooting.

  7. What are the benefits of using Spot VMs, and in what scenarios would they be appropriate?

    • Spot VMs for cost-effective compute resources but with interruption at any time.

  8. How would you handle disk performance issues in Azure VMs?

    • Discuss disk types, performance tiers, resizing, and application tuning.

  9. What is the difference between Azure Standard HDD, Premium SSD, and Ultra Disks?

    • Differences in IOPS, throughput, latency, and costs.

  10. How do you back up and restore Azure VMs?

    • Azure Backup configuration, restoring VMs from snapshots, or using recovery services.