What is RAID and how do the different RAID levels (0, 1, 5, 6, 10) compare in terms of performance and redundancy?

Heisenbug logo
TheHeisenBug

Search

Search across questions, learning content, and hands-on projects

Ace Your Next Tech Interview

5,986+ interview questions across 87 technologies — with expert answers, advanced search, AI-powered assistance, personal highlights, structured learning paths, and hands-on practice projects.

5,986+Questions & Answers
87Technologies
AdvancedSearch
Built-inAsk AI
PersonalHighlights
StructuredLearning Paths
Hands-onPractice Projects

Lifetime Access

One-time payment. No subscriptions. Unlock everything, forever.

$19.90USD

or R$49.90 BRL

FeatureFreePremium
Question titlesAllAll
Answers per topicTop 5All
Learning chaptersFirst 5All
Practice projectsFirst 3All
Highlights✓✓
Ask AI—✓
Read tracking✓✓
Search✓✓

Linux Interview Questions

  1. [JUNIOR] What is Linux and how does it differ from Unix?
  2. [JUNIOR] What is the Linux kernel and what are its main functions?
  3. [JUNIOR] What is the difference between a root user and a regular user in Linux?
  4. [JUNIOR] What is the difference between symbolic links and hard links in Linux?
  5. [JUNIOR] What are the basic file permission types in Linux and how do you read them?
  6. [JUNIOR] How do you check disk usage and free space on a Linux system?
  7. [JUNIOR] What is the sudo command and why is it preferred over logging in as root?
  8. [MID] How do Linux file permissions work, including the numeric (octal) notation, and how do you modify them with chmod?
  9. [MID] How do cron jobs work and how do you schedule recurring tasks using crontab?
  10. [MID] How do you monitor system resources using commands like top, htop, vmstat, and iostat?
  11. [MID] What is load average in Linux and how do you interpret the three numbers it shows?
  12. [MID] How does the systemd init system work and how does it differ from the traditional SysVinit?
  13. [SENIOR] How do you troubleshoot a Linux server experiencing high load average but low CPU utilization?
  14. [SENIOR] How do you harden and secure SSH access on a production Linux server?
  15. [JUNIOR] What are the basic components of the Linux operating system?
  16. [JUNIOR] What is a Linux distribution and how do common distributions differ?
  17. [JUNIOR] What is BASH and how does it differ from other Linux shells?
  18. [JUNIOR] What is swap space in Linux and why is it needed?
  19. [JUNIOR] What is an inode in Linux?
  20. [JUNIOR] What is the grep command and how is it used for text searching?
  21. [JUNIOR] What is a pipe in Linux and how does it enable command chaining?
  22. [JUNIOR] What is a process in Linux and how do you list running processes?
  23. [JUNIOR] How do you find a file by name in Linux?
  24. [MID] How do soft links and hard links differ at the filesystem level in terms of inodes and data blocks?
  25. [MID] What are the different process states in Linux and how does the kernel manage process transitions?
  26. [MID] What is a zombie process, how is it created, and how do you identify and clean up zombie processes?
  27. [MID] How do you configure passwordless SSH authentication between two Linux servers?
  28. [MID] How do you permanently mount filesystems using /etc/fstab?
  29. [MID] What is LVM and how does it simplify disk management in production environments?
  30. [MID] How do you manage services using systemctl commands?
  31. [MID] How do you find which process is listening on a specific port?
  32. [SENIOR] How do you tune Linux kernel parameters using sysctl for performance optimization?
  33. [SENIOR] What is SELinux, how does it differ from traditional DAC permissions, and how do you configure its policies and modes?
  34. [SENIOR] How do you troubleshoot a Linux system that fails to boot?
  35. [SENIOR] How do you use strace to debug application-level issues and trace system calls?
  36. [SENIOR] How do you investigate a suspected security breach on a Linux server?
  37. [JUNIOR] What are the different types of shells available in Linux?
  38. [JUNIOR] What are daemons in Linux and how do they work?
  39. [JUNIOR] What are environment variables in Linux and how do you display them?
  40. [JUNIOR] What are the three standard streams (stdin, stdout, stderr) in Linux?
  41. [JUNIOR] What is the difference between absolute and relative file paths in Linux?
  42. [JUNIOR] What is I/O redirection in Linux and what operators are used for it?
  43. [JUNIOR] What is a package manager and how do RPM-based and Debian-based package managers differ?
  44. [JUNIOR] How do you terminate a process in Linux?
  45. [MID] What is umask and how does it affect default file permissions?
  46. [MID] What are foreground and background processes and how do you manage them using job control?
  47. [MID] How do you create and manage user accounts and groups in Linux?
  48. [MID] What is rsync and how does it differ from scp for file synchronization?
  49. [MID] How do you check and configure network interfaces and IP addresses on a Linux system?
  50. [MID] What is the /proc filesystem and what kind of runtime information does it expose?
  51. [MID] How does log rotation work in Linux and how do you configure logrotate?
  52. [MID] How do you redirect both stdout and stderr to a file or to different destinations?
  53. [MID] What is the /etc/hosts file used for and how does it interact with DNS resolution?
  54. [MID] How do you use the find command with exec to perform bulk operations on matching files?
  55. [SENIOR] How do you extend a logical volume and resize a filesystem without downtime?
  56. [SENIOR] How do you investigate and recover from a kernel panic?
  57. [SENIOR] How do you use tcpdump for network traffic capture and analysis?
  58. [SENIOR] How do you handle centralized log management at scale using syslog and log aggregation tools?
  59. [SENIOR] How do you tune Linux networking stack parameters for high-throughput applications?
  60. [SENIOR] How do you identify and limit resource usage for processes using ulimit and cgroups?
  61. [SENIOR] A production server's disk usage on /var suddenly hits 100%. What steps do you take to diagnose and resolve the issue?
  62. [EXPERT] How do cgroups v1 and v2 work in Linux and how are they used for resource isolation in container runtimes?
  63. [EXPERT] How do Linux namespaces (PID, network, mount, user, UTS, IPC) provide process isolation and what role do they play in container technologies?
  64. [JUNIOR] What is CLI and GUI in the context of Linux?
  65. [JUNIOR] What are hidden files in Linux and how do you view them?
  66. [MID] What is the difference between iptables and nftables?
  67. [MID] How do you troubleshoot DNS resolution issues on a Linux system?
  68. [MID] How do you compress and decompress files and archives using tar, gzip, and bzip2?
  69. [MID] What are sticky bits, setuid, and setgid permissions and when are they used?
  70. [MID] What are runlevels and systemd targets and how do they control the system state?
  71. [MID] How do you add swap space to a running Linux system?
  72. [SENIOR] How do you configure and manage software RAID arrays in Linux?
  73. [SENIOR] How do you perform zero-downtime deployments on Linux servers?
  74. [SENIOR] How would you troubleshoot a service that starts successfully but crashes after running for several hours?
  75. [SENIOR] How do you manage and troubleshoot kernel modules in Linux?
  76. [SENIOR] How do you configure a Linux firewall for a multi-tier application architecture?
  77. [SENIOR] How do you investigate why a server rebooted unexpectedly?
  78. [EXPERT] How do you design a highly available Linux-based infrastructure with automated failover?
  79. [MID] What is the difference between cron and anacron?
  80. [MID] What is NFS and how do you mount a remote NFS share?
  81. [MID] What is the difference between NFS and Samba for network file sharing?
  82. [SENIOR] What is the chroot command and how is it used for process isolation?
  83. [SENIOR] How do you configure NIC bonding or teaming for redundancy and increased throughput?
  84. [SENIOR] How do you perform a kernel upgrade on a production system with minimal risk?
  85. [EXPERT] How does the Linux virtual memory subsystem work, including page tables, TLB, and the OOM killer?
  86. [EXPERT] How do you manage and enforce consistent configuration across a large fleet of Linux servers?
  87. [EXPERT] How do you design Linux systems for horizontal scalability and what kernel tuning is required for high-concurrency workloads?
  88. [SENIOR] What is RAID and how do the different RAID levels (0, 1, 5, 6, 10) compare in terms of performance and redundancy?
  89. [EXPERT] How does the Linux I/O scheduler work and how do you choose between different schedulers for various workloads?
  90. [EXPERT] What is eBPF and how can it be used for observability, networking, and security in Linux?
  91. [EXPERT] How does the Linux boot process work from BIOS/UEFI through bootloader, kernel initialization, to user space?
  92. [EXPERT] How do you troubleshoot performance issues related to NUMA topology on multi-socket Linux systems?