REAL-TIME IBM [ AIX ] Interview Questions & Answers [ STEP-IN ]

Last updated on 26th Jun 2020, Blog, Interview Questions

AIX, short for Advanced Interactive eXecutive, stands as a renowned enterprise-grade Unix-based operating system meticulously crafted by IBM. Celebrated for its unwavering stability and reliability, AIX finds its home on IBM’s Power Systems hardware, where it shines by delivering exceptional performance and scalability, catering to the most demanding and mission-critical workloads. AIX doesn’t just stop at performance; it boasts a suite of advanced features, including dynamic logical partitioning (LPAR) and workload partitioning (WPAR), reinforcing its reputation as a formidable platform. 

1. What is AIX?

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AIX (Advanced Interactive eXecutive) is IBM’s proprietary Unix-based operating system designed for IBM Power Systems, notably IBM’s POWER processor architecture.

2. Explain the role of the System Management Interface Tool (SMIT) in AIX.

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SMIT is a text-based menu-driven interface for managing AIX systems. It simplifies system administration tasks by providing a user-friendly interface for configuration and management.

What is the logical volume in AIX?

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A logical volume is a virtual storage entity in AIX created from one or more physical books. It’s used for file systems and data storage.

4. How can you check the system’s uptime in AIX?

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You can use the uptime or w command to check the system’s uptime and load averages.

5. Explain the purpose of the errpt command in AIX.

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The errpt command is used to display and manage the system error log, providing information about system errors, hardware failures, and other events.

6. How do you add a new user in AIX?

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You can use the mkuser command or edit the /etc/passwd file to add a new user in AIX.

7. What is NIM in AIX, and what is its purpose?

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NIM (Network Installation Manager) is a tool in AIX used for network-based installation, maintenance, and management of AIX systems.

8. Explain the purpose of the chuser command in AIX.

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The chuser command is used to modify user account attributes and properties, such as the user’s password, home directory, or login shell.

9. What is the purpose of the chdev command in AIX?

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The chdev command is used to change device configuration settings, such as attributes of physical devices or logical devices.

10. How can you configure network settings in AIX?

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Network settings can be configured using the smit command or by editing configuration files like /etc/hosts and /etc/hostname.interface.

11. What is the purpose of the mkfs command in AIX?

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The mkfs command is used to create file systems on logical volumes or raw devices in AIX.

12. How do you monitor CPU and memory utilization in AIX?

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You can use commands like topas, vmstat, and nmon to monitor CPU and memory utilization in AIX.

13. What is the purpose of the nohup command in AIX?

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The nohup command is used to run a command in the background, allowing it to continue running even after you log out.

14. How can you check the AIX kernel version?

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To check the kernel version in IBM’s AIX operating system, you can use the uname command with the -a flag. Open a terminal or shell session and enter the following command:

uname -a

This command will display thorough system information, , including the kernel version. The kernel version information will be included in the output, typically in a format like this: AIX hostname 2 7 00C7D5B24C00 AIX hostname 2 7 00C7D5B24C0

In this example, “7” is the kernel version. Depending on the AIX version and setup, the output could differ slightly, but the kernel version number will always be present.

15. What is LPAR (Logical Partitioning) in AIX, and why is it used?

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LPAR is a virtualization technology in AIX that allows you to create multiple virtual partitions on a single physical server, each running its own AIX instance.

16. How do you create a backup in AIX, and what tools are commonly used for this purpose?

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Using mksysb:

Run the mksysb command followed by the destination path to create a system backup image.

For example: mksysb /backup/image_name

Using tar:

To archive and compress files and directories, use the tar command.

Example: tar -cvf /backup/backup_file.tar /path/to/backup

Commonly used tools for AIX backups include mksysb for system backups and tar for file and directory backups. You can also use third-party tools like IBM Tivoli Storage Manager (TSM) for more advanced backup and recovery options.

17. Explain the purpose of the crontab command in AIX.

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• Creating Cron Jobs: The primary purpose of the crontab command is to create new cron jobs. A cron job is essentially a script or command that you want to execute automatically and periodically at specific times or intervals.
• Editing Existing Cron Jobs: Users can use the crontab command to modify existing cron jobs. You can change the schedule, update the command to run, or make other adjustments to the job’s configuration.
• Listing Cron Jobs: You can use crontab -l to list the current user’s cron jobs. This is helpful for reviewing the schedule of tasks that are set to run automatically.
• Removing Cron Jobs: The crontab -r command removes a user’s entire crontab, deleting all scheduled cron jobs associated with that user.
• Copying Cron Jobs: Users can also copy cron jobs from one crontab to another using the crontab -l > file and crontab file commands. This allows you to share or back up cron job configurations.

• Syntax Checking: When you use the crontab command to edit or create a cron job, it performs syntax checking to ensure that the cron job specification is correctly formatted.

18. What is a PVID in AIX?

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PVID stands for Physical Volume Identifier. It is a unique identifier assigned to each physical volume in an AIX system, allowing the system to recognize and manage the physical volumes.

19. Explain the purpose of the crontab files in AIX.

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In AIX, users can have their own crontab files (cron tables) where they can define scheduled tasks to run automatically. These files are stored in the /var/spool/cron/crontabs directory.

20. How do you add a new disk to an existing volume group in AIX?

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You can use the extendvg command to add a new disk to an existing volume group.

 21. What is a JFS log in AIX, and how does it benefit file systems?

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A JFS log, also known as a journal log, is used by Journaled File Systems (JFS) to record file system changes before they are committed to the file system. It helps maintain file system consistency and recover from crashes.

22. What is AIX’s default shell, and how can you change a user’s default shell?

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The default shell in AIX is usually the Bourne shell (/bin/sh). You can change a user’s default shell using the chuser command by modifying the shell attribute.

23. How can you check the available disk space on an AIX system?

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You can use the df command to display disk space usage and the du command to check disk space usage for specific directories.

24. What is the purpose of the mkvg command in AIX?

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The mkvg command is used to create a new volume group in AIX. It associates physical volumes with the new volume group.

25. What is an AIX paging space, and how can you configure it?

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Paging space in AIX is used as virtual memory when physical memory is exhausted. You can configure paging space during system installation or by using the mkps command to add or modify paging length.

26. What is a device descriptor in AIX?

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A device descriptor is a system file used to define attributes and characteristics of devices in AIX. These files are typically located in the /dev directory.

27. How do you change the hostname of an AIX system?

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To change the hostname, you can use the Smitty command and navigate to the “TCP/IP Configuration” menu. Alternatively, you can manually edit the /etc/hostname and /etc/hosts files.

28. What is the purpose of the chfs command in AIX?

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The chfs command is used to change the attributes and characteristics of an existing file system, such as mount options or file system quotas.

29. What is AIX’s Object Data Manager (ODM), and how is it used?

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The ODM is a database used in AIX to store system configuration information. It’s managed using commands like odmadd, odmdelete, and odmget.

30. Explain the role of the inetd process in AIX.

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The Internet process (Internet Services Daemon) manages network services and listens for incoming network requests. When a request is received, it starts the appropriate service.

31. What is the purpose of the mkpath command in AIX?

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The mkpath command is used to create directories, including parent directories, as needed. It ensures that the entire directory path is created if it doesn’t already exist.,/p>

32. How do you configure AIX to automatically start a service at boot time?

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To configure a service to start at boot time, you can use the smitty command to edit the /etc/inittab file or create a script in the /etc/rc.d directory.

33. What is the purpose of the nmon tool in AIX, and how do you use it?

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nmon is a performance monitoring tool in AIX that provides detailed information about system resources, CPU usage, memory, and more. You can run it by simply executing the nmon command.

34. What is the purpose of the /etc/security directory in AIX?

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The /etc/security directory contains security-related configuration files and policies, including user authentication settings and password policies.

35. What is a shared volume group in AIX, and why is it used?

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A shared volume group is a volume group that can be accessed by multiple AIX systems simultaneously. It’s used for clustering and high-availability configurations.

36. How do you list all installed packages on an AIX system?

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You can use the lslpp command with appropriate options to list all installed packages on an AIX system.

37.What is the purpose of the mkuser command in AIX, and what are some common attributes you can set with it?

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The mkuser command is used to create a new user account in AIX. Common attributes that can be set include the username, home directory, login shell, and password.

38. What is AIX LVM (Logical Volume Manager), and how does it work?

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AIX LVM is a system for logical volume and file system management. It works by abstracting physical storage devices (disks) into easily scalable and moveable logical volumes.

39. Explain the purpose of the bootlist command in AIX.

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The bootlist command is used to configure the list of bootable devices for an AIX system. It specifies the order in which devices are tried when the system boots.

40. What is a VGDA in AIX, and why is it important for volume groups?

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VGDA stands for Volume Group Descriptor Area. It contains metadata about a volume group, including information about the volume group’s structure, physical volumes, and logical volumes. It’s critical for the proper functioning of volume groups.

41. How can you list all installed filesets on an AIX system?

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You can use the lslpp -L command to list all installed filesets on an AIX system.

42. Explain the purpose of the crash command in AIX, and when would you use it?

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The crash command is used to analyze system crash dumps and generate diagnostic information for troubleshooting system crashes or hangs.

43. What is AIX’s role in IBM’s Power Systems ecosystem?

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AIX is the primary operating system for IBM Power Systems, which are used for mission-critical workloads, virtualization, and high-performance computing.

44. How do you change the system’s time zone in AIX?

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You can use the smitty command to change the time zone settings in AIX. Alternatively, you can modify the /etc/environment file.

45. Explain the purpose of the ps command in AIX.

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The ps command is used to display information about currently running processes, including their process IDs, CPU and memory usage, and other attributes.

46. What is a nimsh server in AIX, and how is it configured?

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NIM (Network Installation Manager) uses the nimsh server for communication between the NIM master and NIM clients. It can be configured using the nimconfig command.

47. What is a Core Dump in AIX, and how is it generated?

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A Core Dump is a file containing a snapshot of a process’s memory at the time of a crash. It can be generated by setting the coredumpsize ulimit or using the gencore command.

48. Explain the purpose of the mkdvd command in AIX.

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The mkdvd command is used to create an installation DVD image for AIX. It’s particularly useful for system backups and installations.

49. What is PowerVM in AIX, and how does it enhance virtualization capabilities?

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PowerVM is a virtualization technology in AIX that provides advanced virtualization capabilities such as dynamic resource allocation, Live Partition Mobility, and Virtual I/O.

50. How can you add and configure a new network interface in AIX?

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You can use the smitty command to add and configure a new network interface or manually edit the appropriate configuration files like /etc/en0 and /etc/hosts.

51. What is the difference between smit and smitty in AIX?

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smit and smitty are both interfaces for system management in AIX. smit is the command-line version, while smitty provides a text-based menu-driven interface.

52. Explain the purpose of the lssrc command in AIX.

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The lssrc command is used to list the status of subsystems on an AIX system, including information about whether they are active or inactive.

53. How do you create a user with superuser privileges (root) in AIX?

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In AIX, the root user is the superuser by default. You can create additional users with superuser privileges by adding them to the wheel group.

54. What is an AIX configuration profile, and how is it used?

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An AIX configuration profile is a file that stores system configuration settings. It can be used to apply consistent configurations across multiple systems.

55. Explain the purpose of the backup command in AIX.

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The backup command is used to create and manage backup copies of files and directories in AIX. It provides options for full and incremental backups.

56. What is the chvg command used for in AIX?

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The chvg command is used to change the characteristics of a volume group, such as its maximum logical partitions.

57. How can you configure AIX for remote access and administration?

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To configure remote access, you can set up SSH (Secure Shell) for secure remote login, and use tools like smitty or remote desktop solutions for administration.

58. What is AIX’s role in a high-availability (HA) cluster, and how is it configured for HA?

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AIX can be used as an operating system in high-availability clusters to ensure continuous operation of critical applications. Configuration involves tools like PowerHA (formerly known as HACMP) to manage cluster resources and failover.

59. Explain the purpose of the swap space in AIX, and how can you add more swap space to a system?

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Swap space is used as virtual memory when physical memory is exhausted. You can add more swap space using the mkps command or by creating a new paging space.

60. What is an AIX mksysb backup, and how is it created and restored?

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An mksysb backup is a system backup that includes the root file system and essential files. It can be created using the mksysb command and restored using the smit menu or the restvg command.

61. Explain the purpose of the sysdumpdev command in AIX.

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The sysdumpdev command is used to configure and manage the system dump device, which is where kernel crash dump information is written in the event of a system crash.

62. How do you check for and apply software updates (fixes, patches) in AIX?

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AIX updates can be checked using the instfix command, and fixes can be applied using the smitty menu or the installp command.

63. What is the purpose of the chps command in AIX?

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The chps command is used to change the attributes of a paging space, such as its size or priority.

64. What is the difference between AIX’s System Management Interface Tool (SMIT) and the AIX Web-based System Manager (WebSM)?

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SMIT is a text-based, menu-driven tool for system administration, while WebSM provides a web-based interface for system management tasks. Both tools serve similar purposes but offer different interfaces.

65. How do you check the hardware configuration of an AIX system, including CPU, memory, and installed devices?

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You can use the lsattr, lscfg, and prtconf commands to check various aspects of the hardware configuration.

66. What is the purpose of the /etc/inittab file in AIX?

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The /etc/inittab file is used to configure the initialization and startup of system processes, including system runlevels and custom scripts.

67. Explain the role of the audit subsystem in AIX, and how can you enable auditing?

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The audit subsystem in AIX is used for security auditing and monitoring. You can enable auditing using the audit command or the smitty interface.

68. What is the odmget command in AIX, and how is it used?

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The odmget command is used to retrieve information from the Object Data Manager (ODM) database. It allows you to query and display configuration data.

69. How do you configure AIX to automatically start a custom script or application at boot time?

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You can add the script or application to the /etc/inittab file, specifying the appropriate runlevel and script location.

70. What is AIX Live Partition Mobility (LPM), and how does it work?

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High availability and flexibility are guaranteed by the AIX LPM functionality, which enables you to move active AIX partitions from one physical server to another without experiencing any downtime.

71. Explain the purpose of the lqueryvg command in AIX.

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The lqueryvg command is used to display information about physical volumes within a volume group, including their status and properties.

72. What is a VGSA (Volume Group Status Area) in AIX, and why is it important for volume groups?

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VGSA contains metadata that is essential for volume group recovery in case of system crashes. It contributes to preserving the reliability and consistency of volume groups.

73. How can you configure AIX to use a remote NTP (Network Time Protocol) server for time synchronization?

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You can edit the /etc/ntp.conf file to specify remote NTP servers for time synchronization. Additionally, you can use the smit menu for time configuration.

74. Explain the purpose of the chlv command in AIX.

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The chlv command is used to change the attributes of a logical volume, such as its size or allocation policy.

75. What is the purpose of the chjfs command in AIX?

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The chjfs command is used to change the attributes of a Journaled File System (JFS), such as journaling options or mount point settings.

76. How do you monitor and analyze AIX system performance over time?

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Tools like nmon, sar, and topas can be used to monitor and analyze AIX system performance. You can collect and analyze performance data for trends and bottlenecks.

77. What is the role of the hostmibd daemon in AIX, and how does it relate to SNMP (Simple Network Management Protocol)?

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hostmibd is a daemon that supports SNMP on AIX systems, allowing for remote monitoring and management of AIX devices. It interfaces with the SNMP agent to provide SNMP functionality.

 78. What is the purpose of the no command in AIX, and how is it used?

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The no command is used to change network-related settings, such as hostname, IP address, and routing tables. It provides a text-based interface for network configuration.

79. Explain the concept of runlevels in AIX.

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Runlevels in AIX represent different system states or modes of operation. They range from 0 to 9, with each runlevel having a specific purpose, such as single-user mode or multi-user mode.

80. How can you create a custom AIX installation image for automated deployments?

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You can create a custom installation image using tools like NIM (Network Installation Manager) or by customizing a mksysb image with additional packages and configurations.

81. What is the rsh command in AIX, and how can it be used for remote access?

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The rsh command allows remote execution of shell commands on a remote AIX system. However, it’s not recommended due to security concerns, and SSH (Secure Shell) is preferred for remote access.

82. Explain the role of the /etc/security/limits file in AIX.

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The /etc/security/limits file is used to define resource limits for users or groups in AIX, such as maximum CPU time, file size, or memory usage.

83. What is NPIV (N-Port ID Virtualization), and how does it benefit AIX systems?

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NPIV is a technology that allows virtual machines and partitions to have their own Fibre Channel (FC) port. It enhances flexibility and simplifies storage management in AIX systems.

84. WHow can you view and interpret AIX error logs and diagnostic information?

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Error logs can be viewed using the errpt command, and diagnostic information can be analyzed using tools like diag and the Hardware Management Console (HMC).

85. Explain the purpose of the /etc/security/user file in AIX.

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The /etc/security/user file is used to define user account attributes, such as password policies, login restrictions, and user-specific configurations.

86. What is the difference between a soft link and a hard link in AIX?

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A soft link (symbolic link) is a reference to another file or directory, while a hard link is a separate reference to the same underlying data on disk. Changes to the data are reflected in all hard links but not necessarily in soft links.

 87. What is the purpose of the lssrc command in AIX?

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The lssrc command is used to list the status of subsystems and services on an AIX system, including whether they are active or inactive.

88. How can you check the firmware version of an AIX system?

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You can check the firmware version using the prtconf command or by logging into the Hardware Management Console (HMC).

89. What is AIX Workload Partitions (WPARs), and how do they differ from LPARs?

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WPARs are a virtualization technology in AIX that allows you to create isolated, lightweight virtual environments within a single AIX instance. They differ from LPARs in that they share the same kernel and resources as the host AIX system.

90. How do you configure AIX for remote syslog (syslog-ng) forwarding?

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To forward AIX syslog messages to a remote syslog server, you can edit the /etc/syslog.conf file and add the appropriate configuration.

91. What is AIX Trusted Execution, and how does it enhance security?

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AIX Trusted Execution (TE) is a security feature that ensures that only trusted and signed binaries are allowed to execute on the system, reducing the risk of malicious code execution.

92. Explain the purpose of the prtconf command in AIX.

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The prtconf command is used to display system configuration information, including hardware details, memory, and processor information.

93. How can you manage software packages (filesets) in AIX using the installp command?

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You can use the installp command to install, update, and remove software packages (filesets) on an AIX system. It can also be used for listing and querying installed packages.

94. What is the purpose of the mkuser command in AIX, and what are some common attributes you can set with it?

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The mkuser command is used to create new user accounts in AIX. Common attributes that can be set include the username, home directory, login shell, and password.

95. Explain the concept of AIX Workload Partitions (WPAR) mobility.

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WPAR mobility is the ability to move a running workload partition (WPAR) from one AIX system to another without disruption. This is useful for load balancing and maintenance tasks.

96. How do you configure AIX to use DNS for hostname resolution?

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To configure AIX for DNS hostname resolution, you need to edit the /etc/resolv.conf file and specify the DNS server(s) and domain information.

97. What is the purpose of the smcmd command in AIX, and how is it used?

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The smcmd command is used to interact with the AIX System Management Command Interpreter (SMIT). It allows you to execute SMIT tasks from the command line, automating system management tasks.