Linux Questions with Answers:-
1. Define what is Linux?
Linux is an operating system based on UNIX and was first introduced by Linus Torvalds. It is based on the Linux Kernel and can run on different hardware platforms manufactured by Intel, MIPS, HP, IBM, SPARC and Motorola. Another popular element in Linux is its mascot, a penguin figure named Tux.
2. Define what is the difference between UNIX and LINUX?
Unix originally began as a propriety operating system from Bell Laboratories, which later on spawned into different commercial versions. On the other hand, Linux is free, open source and intended as a non-propriety operating system for the masses.
3. Define what is BASH?
BASH is short for Bourne Again SHell. It was written by Steve Bourne as a replacement to the original Bourne Shell (represented by /bin/sh). It combines all the features from the original version of Bourne Shell, plus additional functions to make it easier and more convenient to use. It has since been adopted as the default shell for most systems running Linux.
4. Define what is Linux Kernel?
The Linux Kernel is a low-level systems software whose main role is to manage hardware resources for the user. It is also used to provide an interface for user-level interaction.
5. Define what is LILO?
LILO is a boot loader for Linux. It is used mainly to load the Linux operating system into main memory so that it can begin its operations.
6. Define what is a swap space?
Swap space is a certain amount of space used by Linux to temporarily hold some programs that are running concurrently. This happens when RAM does not have enough memory to hold all programs that are executing.
7. Define what is the advantage of open source?
Open source allows you to distribute your software, including source codes freely to anyone who is interested. People would then be able to add features and even debug and correct errors that are in the source code. They can even make it run better and then redistribute these enhanced source code freely again. This eventually benefits everyone in the community.
8. Define what are the basic components of Linux?
Just like any other typical operating system, Linux has all of these components: kernel, shells and GUIs, system utilities, an application program. Define what makes Linux advantageous over other operating system is that every aspect comes with additional features and all codes for these are downloadable for free.
9. Does it help for a Linux system to have multiple desktop environments installed?
In general, one desktop environment, like KDE or Gnome, is good enough to operate without issues. It’s all a matter of preference for the user, although the system allows switching from one environment to another. Some programs will work on one environment and not work on the other, so it could also be considered a factor in selecting which environment to use.
10. Define what is the basic difference between BASH and DOS?
The key differences between the BASH and DOS console lie in 3 areas:
- BASH commands are case sensitive while DOS commands are not;
- under BASH, / character is a directory separator and acts as an escape character. Under DOS, / serves as a command argument delimiter and is the directory separator
- DOS follows a convention in naming files, which is 8 character file name followed by a dot and 3 characters for the extension. BASH follows no such convention.
11. Define what is the importance of the GNU project?
This so-called Free software movement allows several advantages, such as the freedom to run programs for any purpose and freedom to study and modify a program to your needs. It also allows you to redistribute copies of the software to other people, as well as the freedom to improve software and have it released to the public.
12. Explain the root account.
The root account is like a systems administrator account and allows you full control of the system. Here you can create and maintain user accounts, assigning different permissions for each account. It is the default account every time you install Linux.
13. Define what is CLI?
CLI is short for Command Line Interface. This interface allows the user to type declarative commands to instruct the computer to perform operations. CLI offers an advantage in that there is greater flexibility. Define, However, other users who are already accustom with using GUI find it difficult to remember commands including attributes that come with it.
14. Define what is GUI?
GUI, or Graphical User Interface, makes use of images and icons that users click and manipulate as a way of communicating with the computer. Instead of having to remember and type commands, the use of graphical elements makes it easier to interact with the system, as well as adding more attraction through images, icons, and colors.
15. Define How do you open a command prompt when issuing a command?
To open the default shell (which is where the command prompt can be found), press Ctrl-Alt-F1. This will provide a command line interface (CLI) from which you can run commands as needed.
16. Define How can you find out Define How much memory Linux is using?
From a command shell, use the “concatenate” command: cat /proc/meminfo for memory usage information. You should see a line stating something like Mem: 64655360, etc. This is the total memory Linux thinks it has available to use.
17. Define what is a typical size for a swap partition under a Linux system?
The preferred size for a swap partition is twice the amount of physical memory available on the system. If this is not possible, then the minimum size should be the same as the amount of memory installed.
18. Define what are symbolic links?
Symbolic links act similarly to shortcuts in Windows. Such links point to programs, files or directories. It also allows you instant access to it without having to go directly to the entire pathname.
19. Does the Ctrl+Alt+Del key combination work on Linux?
Yes, it does. Just like Windows, you can use this key combination to perform a system restart. One difference is that you won’t be getting any confirmation message and therefore, a reboot is immediate.
20. Define How do you refer to the parallel port where devices such as printers are connected?
Whereas under Windows you refer to the parallel port as the LPT port, under Linux you refer to it as /dev/lp. LPT1, LPT2 and LPT3 would therefore be referred to as /dev/lp0, /dev/lp1, or /dev/lp2 under Linux.
21. Are drives such as hard drive and floppy drives represented with drive letters?
No. In Linux, each drive and device has different designations. For example, floppy drives are referred to as /dev/fd0 and /dev/fd1. IDE/EIDE hard drives are referred to as /dev/hda, /dev/hdb, /dev/hdc, and so forth.
22. Define How do you change permissions under Linux?
Assuming you are the system administrator or the owner of a file or directory, you can grant permission using the chmod command. Use + symbol to add permission or – symbol to deny permission, along with any of the following letters: u (user), g (group), o (others), an (all), r (read), w (write) and x (execute). For example, the command chmod go+rw FILE1.TXT grants read and write access to the file FILE1.TXT, which is assigned to groups and others.
23. In Linux, Define what names are assigned to the different serial ports?
Serial ports are identified as /dev/ttyS0 to /dev/ttyS7. These are the equivalent names of COM1 to COM8 in Windows.
24. Define How do you access partitions under Linux?
Linux assigns numbers at the end of the drive identifier. For example, if the first IDE hard drive had three primary partitions, they would be named/numbered, /dev/hda1, /dev/hda2 and /dev/hda3.
25. Define what are hard links?
Hard links point directly to the physical file on disk, and not on the path name. This means that if you rename or move the original file, the link will not break since the link is for the file itself, not the path where the file is located.
26. Define what is the maximum length for a filename under Linux?
Any filename can have a maximum of 255 characters. This limit does not include the path name, so therefore the entire pathname and filename could well exceed 255 characters.
27. Define what are filenames that are preceded by a dot?
In general, filenames that are preceded by a dot are hidden files. These files can be configuration files that hold important data or setup info. Setting these files as hidden makes it less likely to be accidentally deleted.
28. Define a virtual desktop.
This serves as an alternative to minimizing and maximizing different windows on the current desktop. Using virtual desktops, each desktop is a clean slate where you can open one or more programs. Rather than minimizing/restoring all those programs as needed, you can simply shuffle between virtual desktops with programs intact in each one.
29. Define How do you share a program across different virtual desktops under Linux?
To share a program across different virtual desktops, in the upper left-hand corner of a program window look for an icon that looks like a pushpin. Pressing this button will “pin” that application in place, making it appear in all virtual desktops, in the same position onscreen.
30. Define what does a nameless (empty) directory represent?
This empty directory name serves as the nameless base of the Linux file system. This serves as an attachment for all other directories, files, drives, and devices.
31. Define what is the pwd command?
The pwd command is short for print working directory command. Its counterpart in DOS is the cd command and is used to display the current location in the directory tree.
32. Define what are daemons?
Daemons are services that provide several functions that may not be available under the base operating system. Its main task is to listen for service request and at the same time to act on these requests. After the service is done, it is then disconnected and waits for further requests.
33. Define How do you switch from one desktop environment to another, such as switching from KDE to Gnome?
Assuming you have these two environments installed, just log out from the graphical interface. Then at the Log in the screen, type your login ID and password and choose which session type you wish to load. This choice will remain your default until you change it to something else.
34. Define what are the kinds of permissions under Linux?
There are 3 kinds of permissions under Linux:
- Read: users may read the files or list the directory
- Write: users may write to the file of new files to the directory
- Execute: users may run the file or lookup a specific file within a directory
35. Define How does case sensitivity affect the way you use commands?
When we talk about case sensitivity, commands are considered identical only if every character is encoded as is, including lowercase and uppercase letters. This means that CD, cd, and Cd are three different commands. Entering a command using uppercase letters, where it should be in lowercase, will produce different outputs.
36. Define what are environmental variables?
Environmental variables are global settings that control the shell’s function as well as that of other Linux programs. Another common term for environmental variables is global shell variables.
37. Define what are the different modes when using vi editor?
There are 3 modes under vi:
- Command mode: this is the mode where you start in
- Edit mode: this is the mode that allows you to do text editing
- Ex mode: this is the mode wherein you interact with vi with instructions to process a file
38. Is it possible to use a shortcut for a long pathname?
Yes, there is. A feature known as filename expansion allows you to do this using the TAB key. For example, if you have a path named /home/Iceman/assignments directory, you would type as follows: /ho[tab]/ice[tab]/assi[tab] . This, Define, However, assumes that the path is unique and that the shell you’re using supports this feature.
39. Define what is redirection?
Redirection is the process of directing data from one output to another. It can also be used to direct output as an input to another process.
40. Define what is grep command?
grep a search command that makes use of pattern-based searching. It makes use of options and parameters that are specified along the command line and applies this pattern into searching the required file output.
41. Define what could possibly be the problem when a command that was issued gave a different result from the last time it was used?
One highly possible reason for getting different results from Define what seems to be the same command has something to do with case sensitivity issues. Since Linux is case sensitive, a command that was previously used might have been entered in a different format from the present one. For example, to lists all files in the directory, you should type the command ls, and not LS. Typing LS would either result in an error message if there is no program by that exact name exist or may produce a different output if there is a program named LS that performs another function.
42. Define what are the contents in /usr/local?
It contains locally installed files. This directory actually matters in environments where files are stored on the network. Specifically, locally-installed files go to /usr/local/bin, /usr/local/lib, etc.). Another application of this directory is that it is used for software packages installed from source, or software not officially shipped with the distribution.
43. Define How do you terminate an ongoing process?
Every process in the system is identified by unique process id or paid. Use the kill command followed by the pad in order to terminate that process. To terminate all process at once, use kill 0.
44. Define How do you insert comments in the command line prompt?
Comments are created by typing the # symbol before the actual comment text. This tells the shell to completely ignore Define what follows. For example “# This is just a comment that the shell will ignore.”
45. Define what is command grouping and Define How does it work?
You can use parentheses to group commands. For example, if you want to send the current date and time along with the contents of a file named OUTPUT to a second file named MY DATES, you can apply command grouping as follows: (date cat OUTPUT) > MY DATES
46. Define How do you execute more than one command or program from a single command line entry?
You can combine several commands by separating each command or program using a semicolon symbol. For example, you can issue such a series of commands in a single entry:
ls –l cd .. ls –a MYWORK which is equivalent to 3 commands: ls -l cd.. ls -an MYWORK
47. Write a command that will look for files with an extension “c”, and has the occurrence of the string “apple” in it.
Find ./ -name “*.c” | xargs grep –i “apple”
48. Write a command that will display all .txt files, including its individual permission.
ls -a -l *.txt
49. Write a command that will do the following:
-look for all files in the current and subsequent directories with an extension c,v
-strip the,v from the result (you can use sed command)
-use the result and use a grep command to search for all occurrences of the word ORANGE in the files.
Find ./ -name “*.c,v” | sed ‘s/,v//g’ | xargs grep “ORANGE”
50. Define what, if anything, is wrong with each of the following commands?
a) ls -l-s
b) cat file1, file2
c) ls – s Factdir
a) there should be space between the 2 options: ls -ls
b) do not use commas to separate arguments: cat file1 file2
c) there should be no space between hyphen and option label: ls –s Factdir
51. Define what is the command to calculate the size of a folder?
To calculate the size of a folder using the command dush folder1.
52. Define How can you find the status of a process?
Use the command
ps ux
53. Define How can you check the memory status?
You can use the command
free -m to display output in MB
free -g to display output in GB
54. Define How to color the Git console?
To color the Git console you can use the command git config—global color.UI auto. In the command, the color.UI variable sets the default value for variables such as color.diff and color.grep.
55. Define How can you append one file to another in Linux?
To append one file to another in Linux you can use command cat file2 >> file 1. The operator >> appends the output of the named file or creates the file if it is not created. While another command cat file 1 file 2 > file 3 appends two or more files to one.
56. Define How you can find a file using Terminal?
To find a file you have to use a command, find. –name “process.txt”. It will look for the current directory for a file called process.txt.
57. Define How you can create a folder using Terminal?
To create a folder, you have to use command mkdir. It will be something like these: ~$ mkdir Guru99
58. Define How you can view the text file using Terminal?
To view the text file, go to the specific folder where the text files are located by using the command cd and then type less filename.txt.
59. Define How to enable curl on Ubuntu LAMP stack?
To enable curl on Ubuntu, first, install libcurl, once done use following command sudo/etc/init .d /apache2 restart or sudo service apache2 restart.
60. Define How to enable root logging in Ubuntu?
The command which enables root logging is
#sudo sh-c ‘echo “greater-sDefine How-manual-login=true” >>/etc/lightdm/lightdm.conf’
61. Define How you can run a Linux program in the background simultaneously when you start your Linux Server?
By using nohup. It will stop the process receiving the NOHUP signal and thus terminating it you log out of the program which was invoked with. & runs the process in the background.
62. Define How to uninstall the libraries in Linux?
To uninstall the libraries in Linux, you can use command sudo apt-get remove library_name
63. I want to connect to a remote server and execute some commands, Define How can I achieve this?
We can use telnet to do this:
telnet hostname –luser
>Enter password
>Write the command to execute
>quit
64. I have 2 files and I want to print the records which are common to both.
We can use “comm” command as follows:
comm -12 file1 file2 … 12 will suppress the content which is
unique to 1st and 2nd file respectively.
65. Write a script to print the first 10 elements of Fibonacci series.
Make one file in Vi editor myscript.sh
#!/bin/sh
a=1
b=1
echo $a
echo $b
for I in 1 2 3 4 5 6 7 8
do
c=a
b=$a
b=$(($a+$c))
echo $b
done
LINUX Questions pdf free download ::
66. Define what are the 3 standard streams in Linux?
- Standard Input
- Standard Output
- Standard Error
67. Define what is the use of clustering?
Clustering is the use of multiple storage devices and redundant interconnections. Also can be used for storage, load balancing high availability and High performance.
68. I want to read all input to the command from file1 direct all output to file2 and error to file 3, Define How can I achieve this?
command <file1 1>file2 2>file3
69. Given a file find the count of lines containing the word “ABC”.
grep –c “ABC” file1
70. Define what is the difference between grep and egrep?
egrep is Extended grep that supports added grep features like “+” (1 or more occurrence of the previous character),”?”(0 or 1 occurrence of the previous character) and “|” (alternate matching)
71. Define How will you find the total disk space used by a specific user?
$ du -s /home/user1 ….where user1 is the user for whom the total disk
space needs to be found.
72. Define How will I insert a line “ABCDEF” at every 100th line of a file?
$ sed ‘100iABCDEF’ file1
73. Write a command sequence to find all the files modified in less than 2 days and print the record count of each.
find. –mtime -2 –exec wc –l {} ;
74. Define How can I set the default rwx permission to all users on every file which is created in the current shell?
We can use: umask 777
This will set default rwx permission for every file which is created to every user.
75. Define How can we find the process name from its process id?
We can use “ps –p ProcessId”
76. Define How can I send a mail with a compressed file as an attachment?
zip file1.zip file1|mailx –s “subject” Recipients email id
Email content
EOF
77. Define How do we create command aliases in the shell?
alias Aliasname=” Command whose alias is to be created”
Ex :- alias server_path=/home/tom/apache
78. Which is the standard command used to uncompress gzip files?
The standard command used to uncompress gzip files is gunzip.
79. Define what is the command used to install an RPM package named demofilename2.2-2.i386.rpm?
The most common command used to install an RPM package is rpm -ivh. Following command will install the given package
#rpm -ivh demofilename2.2-2.i386.rpm
80. When attempting to connect to www.example.com you got unknown host message. Which service is most likely not functioning properly?
DNS – Domain Name Service
81. Name one of the most secure methods of remote access.
SSH is the most secure method of remote access
82. Define what command is used to exit the edit mode of VI editor?
The [esc] key is used to exit from the edit mode of VI editor.
83. Define what key combination will exit from VI editor and not save the changes made?
Esc + q +! The key combination will exit VI without saving the changes.
84 Where is the file? bashrc located?
The . bashrc file is usually located in the /home/username directory.
85. Define what function does the .bash_profile file perform?
The function of the .bash_profile file is to provide login initialization commands.
86. Define what function does the .bash_logout file perform?
The function of the .bash_logout is to provide logout functions
87. Define what function does the .bashrc file perform?
The function of the .bashrc file is to provide shell configuration commands.
88. Define what are the default ports used for SMTP, DNS, FTP, DHCP, SSH, and squid?
Service Port
————————–
SMTP 25
DNS 53
FTP 20 (data transfer) , 21 ( Connection established)
DHCP 67/UDP(DHCP server), 68/UDP(DHCP client)
SSH 22
Squid 3128
89. Define How to check which ports are listening in my Linux Server?
Use the Command ‘netstat –listen’ and ‘lsof -i’
90. Define How to check file system and space available on it.
[root@linux-world ~]# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/vg00-root 17003304 804668 15311852 5% /
devtmpfs 771876 0 771876 0% /dev
tmpfs 777928 0 777928 0% /dev/shm
tmpfs 777928 8532 769396 2% /run
tmpfs 777928 0 777928 0% /sys/fs/cgroup
/dev/mapper/vg00-home 14987616 41000 14162232 1% /home
/dev/sda1 487652 62593 395363 14% /boot
/dev/mapper/vg00-var 9948012 48696 9370932 1% /var
/dev/mapper/vg00-sap 14987656 37636 14165636 1% /sap
91. Tell me the steps to remove the swap file?
Ans. Firstly disable the swap file by “swapoff” command.
Remove Swap file entry from /etc/fstab file.
Now remove the swap file by “rm” command.
92. Define How you can find a file using Terminal?
To find a file you have to use a command, find. –name “process.txt”. It will look for the current directory for a file called process.txt.
93. Define How you can create a folder using Terminal?
To create a folder, you have to use command mkdir. It will be something like these: ~$ mkdir Guru99
94. Define How you can view the text file using Terminal?
To view the text file, go to the specific folder where the text files are located by using the command cd and then type less filename.txt.
95. Define How to enable curl on Ubuntu LAMP stack?
To enable curl on Ubuntu, first, install libcurl, once done use following command sudo/etc/init .d /apache2 restart or sudo service apache2 restart.
96. Define How to enable root logging in Ubuntu?
The command which enables root loging is
#sudo sh-c ‘echo “greater-sDefine How-manual-login=true” >>/etc/lightdm/lightdm.conf’
97. Why LVM is required ?
Ans: LVM stands for Logical Volume Manager, to resize filesystem’s size online we required LVM partition in Linux. Size of LVM partition can be extended and reduced using the lvextend & lvreduce commands respectively.
98. Define How To check Memory stats and CPU stats?
Ans: Using ‘free’ & ‘vmstat’ command we can display the physical and virtual memory statistics respectively. With the help of ‘sar’ command, we see the CPU utilization & other stats.
99. Define How to increase the size of LVM partition?
Ans: Below is the Logical Steps :
- Use the lvextend command (lvextend -L +100M /dev/<Name of the LVM Partition>, in this example we are extending the size by 100MB.
- resize2fs /dev/<Name of the LVM Partition>
- check the size of a partition using ‘df -h’ command
100. Define what does Sar provides and at which location Sar logs are stored?
Ans: Sar Collect, report, or save system activity information. The default version of the car command (CPU utilization report) might be one of the first facilities the user runs to begin system activity investigation because it monitors major system resources. If CPU utilization is near 100 percent (user + nice + system), the workload sampled is CPU-bound.
By default log files of Sar command is located at /var/log/sa/sad file, where the dd parameter indicates the current day.
101. Define what are manifests in Puppet?
Manifests in Puppet are the files in which the client configuration is specified.
102. Which Command is used to sign requested certificates in Puppet Server?
‘puppetca –sign hostname-of-agent’ in (2.X) & ‘puppet ca sign hostname-of-agent’ in (3.X)
103. At which location Puppet Master Stores Certificates?
/var/lib/puppet/ssl/ca/signed
104. Define How to find all the regular files in a directory?
using the command ‘find /<directory -type f’.
105. Define How to reduce or shrink the size of LVM partition?
Below are the logical Steps to reduce the size of the LVM partition :
-Umount the filesystem using umount command,
-use resize2fs command , e.g resiz2fs /dev/mapper/myvg-mylv 10G
-Now use the reduce command, e.g lvreduce -L 10G /dev/mapper/myvg-mylv
Above Command will shrink the size & will make the filesystem size 10GB.
106. Define How to create the partition from the raw disk?
Using disk utility we can create partitions from the raw disk. Below are the steps to create the partition from the raw disk :
- fdisk /dev/hd* (IDE) or /dev/sd* (SCSI)
- Type n to create a new partition
- After creating partition, type w command to write the changes to the partition table.
107. Where the kernel modules are located?
The ‘/lib/modules/kernel-version/’ directory stores all kernel modules or compiled drivers in Linux operating system. Also with ‘lsmod’ command, we can see all the installed kernel modules.
108. Define what is umask?
mask stands for ‘User file creation mask’, which determines the settings of a mask that controls which file permissions are set for files and directories when they are created.
109. Define How to set the mask permanently for a user?
To set this value permanently for a user, it has to be put in the appropriate profile file which depends on the default shell of the user.
110. Define How to change the default run level in Linux?
To change the run level we have to edit the file “/etc/inittab” and change initdefault entry ( id:5:initdefault:). Using ‘init’ command we change the run level temporary like ‘init 3’, this command will move the system in run level 3.
111. Define How to share a directory using NFS?
To share a directory using NFS, first edit the configuration file ‘/etc/exportfs’, add an entry like
‘/<directory-name> <ip or Network>(Options)’ and then restart the NFS service.
112. Define How to check and mount NFS share?
Using ‘sDefine Howmount’ command we can see Define what directories are shared via NFS e.g ‘sDefine Howmount -e <ip address of NFS server>’.Using mount command we can mount the NFS share on a Linux machine.
113. Define what is load average in a Linux?
Load Average is defined as the average sum of the number of process waiting in the run queue and number of a process currently executing over the period of 1,5 and 15 minutes. Using the ‘top’ and ‘uptime’ command we find the load average of a Linux server.
114. Define what is Network Bonding?
Network bonding is the aggregation of multiple Lan cards into a single bonded interface to provide fault tolerance and high performance. Network bonding is also known as NIC Teaming.
115. Define what are the different modes of Network bonding in Linux?
Below is a list of modes used in Network Bonding :
balance-rr or 0 – round-robin mode for fault tolerance and load balancing.
active-backup or 1 – Sets the active-backup mode for fault tolerance.
balance-xor or 2 – Sets an XOR (exclusive-or) mode for fault tolerance and load balancing.
broadcast or 3 – Sets a broadcast mode for fault tolerance. All transmissions are sent on all slave interfaces.
802.3ad or 4 – Sets an IEEE 802.3ad dynamic link aggregation mode. Creates aggregation groups that share the same speed & duplex settings.
balance-tub or 5 – Sets a Transmit Load Balancing (TLB) mode for fault tolerance & load balancing.
balance-alb or 6 – Sets an Active Load Balancing (ALB) mode for fault tolerance & load balancing.
116. Define How to check and verify the status of the bond interface.
Using the command ‘cat /proc/net/bonding/bond0’, we can check which mode is enabled and Define what line cards are used in this bond. In this example, we have one only one bond interface but we can have multiple bond interface like bond1,bond2 and so on.
117. Define How to check the default route and routing table?
Using the Commands ‘netstat -nr’ and ‘route -n’ we can see the default route and routing tables.
118. Define How to check which ports are listening in my Linux Server?
Use the Command ‘netstat –listen’ and ‘lsof -i’
119. List the services that are enabled at a particular run level in Linux server?
With the help of command ‘chkconfig –list | grep 5: on’ we can list all the service that is enabled in run level5. For other run levels just replace 5 with the respective run level.
120. Define How to enable service at a particular run level?
We can enable a service using the Command ‘chkconfig <Service-Name> on –level 3’
121. Define How to upgrade Kernel in Linux?
We should never upgrade Linux Kernel, always install the new New kernel using rpm command because upgrading a kernel can make your Linux box in an unbootable state.
122. Define How To scan newly assigned runs on Linux box without rebooting?
There are two ways to scan newly assigned runs :
Method:1 if sg3 rpm is installed, then run the command ‘rescan-SCSI-bus.sh’
Method:2 Run the Command , echo ” – – – ” > /sys/class/scsi_host/hostX/scan
123. Define How to find WWN numbers of HBA cards in Linux Server?
We can find the WWN numbers of HBA cards using the command ‘systool -c fc_host -v | grep port_name’
124. Define How to add & change the Kernel parameters?
To Set the kernel parameters in Linux, first edit the file ‘/etc/sysctl.conf’ after making the changes save the file and run the command ‘sysctl -p’, this command will make the changes permanently without rebooting the machine.
125. Define what is Puppet Server?
Puppet is an open-source & enterprise software for configuration management tool in UNIX like operating system. Puppet is an IT automation software used to push the configuration to its clients (puppet agents) using code. Puppet code can do a variety of tasks from installing new software, to check file permissions, or updating user accounts & lots of other tasks.