IBM AIX Interview Questions and Answers
Q: – What is IBM AIX ?
AIX(Advanced Interactive eXecutive) is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms. Originally released for the IBM 6150 RISC workstation, AIX now supports or has supported a wide variety of hardware platforms, including the IBM RS/6000 series and later IBM POWER and PowerPC-based systems, IBM System i, System/370 mainframes, PS/2 personal computers, and the Apple Network Server. AIX is based on UNIX System V with 4.3BSD-compatible extensions. It is one of four commercial operating systems that are presently certified to The Open Group's UNIX 03 standard (The others are Mac OS X, Solaris and HP-UX.)
Q: – What is System Management Interface Tool (SMIT) ?
SMIT is the System Management Interface Tool for AIX. It allows a user to navigate a menu hierarchy of commands, rather than using the command line. Invocation is typically achieved with the command smit. Experienced system administrators make use of the F6 function key which generates the command line that SMIT will invoke to complete the proposed task. SMIT also generates a log of commands that are performed in the smit.script file. The smit.script file automatically records the commands with the command flags and parameters used. The smit.script file can be used as an executable shell script to rerun system configuration tasks. SMIT also creates the smit.log file, which contains additional detailed information that can be used by programmers in extending the SMIT system.
Q: – What are the unique features of AIX ?
The following are some unique system management features of AIX.
1.Logical Volume Manager :- The Logical Volume Manager (LVM) maintains the hierarchy of logical structures that manage disk storage.
2. System Resource Controller:- The System Resource Controller (SRC) provides a set of commands and subroutines for creating and controlling subsystems and is designed to minimize the need for human intervention in system processing.
3. Object Data Manager :- The Object Data Manager (ODM) is a data manager intended for the storage of system data.
4.Software Vital Product Data:- Certain information about software products and their installable options is maintained in the Software Vital Product Data (SWVPD) database.
5.Workload management :- Workload Manager (WLM) is designed to provide the system administrator with increased control over how the scheduler virtual memory manager (VMM) and the disk I/O subsystem allocate resources to processes. You can use WLM to prevent different classes of jobs from interfering with each other and to allocate resources based on the requirements of different groups of users.
6.Operating system updates:- The operating system package is divided into filesets, where each fileset contains a group of logically related customer deliverable files. Each fileset can be individually installed and updated.
Q: – How to configure a read/write optical drive ?
There are two methods for configuring a read/write optical drive. The read/write optical drive must be connected to the system and powered on.
Method 1:-Method one is the faster of the two methods. It only configures the read/write optical drive specified. To use this method, you must provide the following information:
Subclass Defines how the drive is attached.
Type Specifies the type of read/write optical drive.
Parent Name Specifies the system attachment the drive is connected to.
Where Connected Specifies the logical address of the drive.
Enter the following command to configure the read/write optical drive:
mkdev -c rwoptical -s Subclass -t Type -p ParentName -w WhereConnected
The following is an example of a read/write optical drive that has a SCSI ID of 6, a logical unit number of zero, and is connected to the third (scsi3) SCSI bus:
mkdev -c rwoptical -s scsi -t osomd -p scsi3 -w 6,0 -a pv=yes
Method 2 :- Method two uses the Configuration Manager, searching the current configuration, detecting any new devices, and automatically configuring the devices. This method is used when little information is known about the read/write optical drive.
a)Use the configuration manager to configure all newly detected devices on the system (including the read/write optical drive) by typing:
b)Type the following command to list the names, location codes, and types of all currently configured read/write optical drives:
lsdev -C -c rwoptical
c)Determine the name of the newly configured read/write optical drive using the location code that matches the location of the drive being added.
Q: – Explain the AIX file system.
– AIX uses a hierarchical file tree that consists of directories, subdirectories and files.
– The top level directory is called the root (/) directory that has many subdirectories.
– The file tree is mounted during the system startup.
Q: – What are the keyboard shortcuts used on AIX terminal ?
– Backspace : to correct mistakes.
– <ctrl+c> : terminates the correct command and return to the shell.
– <ctrl+d> : end of transmission or end of file
– <ctrl+s> : temporary stops the output to the screen
– <ctrl+q> : resumes output which was stopped by ctrl+s
– <ctrl+u>: erases the entire line.
Q: – What are the logging in and Out commands in AIX.
To login in:
Login id: <username>
Password: <the password does not appear>
To log out:
$ <ctrl+d> (or)
$ <exit> (or)
– AIX is designed as a multiuser system, a level of security is implemented to control access. Each user of the system has a user name and associated password (optional).
– If the user ID requires a password, the system will prompt for the password in a similar manner. While the user is typing a password, it does not appear on the screen.
– To terminate the session the user may either enter the exit or logout command, or press the key combination <Ctrl-d> (holding down the Ctrl key while pressing the d key.) logout only works if you are in your login shell.
Q: – Define commands and Process in AIX ?
A command is a request to perform an operation or run a program. A process is a program or command that is actually running on the computer.We use commands to tell the operating system what task you want it to perform. When commands are entered, they are deciphered by a command interpreter (also known as a shell), and that task is processed.
The operating system can run many different processes at the same time. The operating system allows you to manipulate the input and output (I/O) of data to and from your system by using specific I/O commands and symbols. You can control input by specifying the location from which to gather data. For example, you can specify to read input entered on the keyboard (standard input) or to read input from a file. You can control output by specifying where to display or store data. For example, you can specify to write output data to the screen (standard output) or to write it to a file.
Commands :- Some commands can be entered simply by typing one word. It is also possible to combine commands so that the output from one command becomes the input for another command.
Processes :- A program or command that is actually running on the computer is referred to as a process.
Q: – What is Server Message Block file system(SMBFS) in AIX ?
Server Message Block Filesystem (SMBFS) allows access to shares on SMB servers as local filesystems on AIX. In this filesystem, the user can create, delete, read, write, and modify the access times of files and directories. The owner or access mode of files and directories cannot be changed.
SMBFS can be used to access files on an SMB server. The SMB server is a server running Samba; an AIX server running AIX Fast Connect; or a Windows XP, Windows NT, or Windows 2000 server or workstation. Each of these server types allows a directory to be exported as a share. This share can then be mounted on an AIX system using SMBFS.
SMBFS installation :- To install SMBFS on an AIX system, install the bos.cifs_fs package.
SMBFS mounting :- The Server Message Block Filesystem (SMBFS) can be mounted in one of two ways.
Stored passwords :- SMBFS can store server/user/password credentials in the /etc/cifs_fs/cifscred file to allow automatic retrieval of passwords when mounting SMBFS.
/etc/filesystems support :- SMBFS supports /etc/filesystems to allow automated mounting at system startup.
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