Linux interview Questions

 Linux inetrview questions:


1).How can I revoke file permission on a dirextory or a file for one user?


so if you want to revoke the file permiison,


so we can execute the command like as the,


chmod o-x filename 


so in this way we can revoke file permission or a


directory permissions from a one user.


which means the acl is set on this file . so that's why patrticular user doesn't access the

file 


if you are listing the file , we can see the +1 options which means , the acl is enable on this file 



2).

any files are ends with +1 which means we are enable on the


acl on this particular file or directory


all userss having the access for the files and directory


but ram users are doesn't . because the acl or enable on this file


3).how to setfacl ,getfacl amd sticky bit in linux os ?


we can execute the command like as the,


setfacl -m u:ram:rwx filename 


in this way we can set it to the acl on this particuat

file 


4)how to check if acl is etting on this pativulat file1


we can execute the command like as the


getfacl filename 



it will list out the what is the fileanme

who is user 


who is yje owner of this file


then it will display the permssions for userss ,group and others


chattr command:

 


once the chattr command is implemented on this file,


definirlty this file is not going to be deleted


its shows the opratiosn not permitted


once chattr command on remove on this file ,


the file will be automatically deleted



lsattr


it will lsit out the file attributes 


6).How can i inherit group on filesystem?


so we can execute the comamnd likea sthe ,

fist we ned to crtae the group called as the


groupadd comamnd 


next we need to carete the directory


chmos g+s test / -R


in this way we can inherit the group on filesystem


next we can execute the command like asthe ,


chown jeey rest/

now give ll


yes successfully the group inherited into filesystem



7).How cna i ebanble acl on this filessyetm?


setfacl -m u:ram:rwx filename 


in this way we can enable the acl on this filesystem


or else if you want to check it out the whather the acl is enable on file or not ,


so we can execute the comand like as the,


getfacl file or filesystem command in linux os 



8).How can I set quota for a user in linux?


edquota username


set quota for a user:


edquota -g groupname


if you want to check the user having the quota or not we have to check it out the


cat /etc


u can ebale quota into fstab filessytem 


9).what is the differnece between sgib and suid in linux ios?


values for suid and sgid and stickybit 


suid =4

sgid=2

stickybit =1

chmod u+s filename

chmod g+s hilename


suid:


this is specila permisisn . this permisison enables on the 


partoicular enable on the exdcutables files. once this suid permission is enable on the executanle

files , then normal user gettimg temprity priviliges accesss to the file owner or root owner.


sgid :

particilar user enable on the excutanle file and directories . once this permsiion is enable on the

executable file or directories then normal user getetn tempeiry priviliges access to group ownership


10).



monitroing and managing the linux process:


1).How to check the all running process in linux os?



top


ps -ef 


in this way we can check it out the all running process in linux os 


2).How can I chnage the priroty of running process?


we can execute the command like as the,

renice nicevalue processid 


3).what is the range of nice value in linux os ?


-20 to +20 

-20 means = hightest nice value 


+20 means = lowest nice value 


normal user can set it -19 to +19 

root user can set it -20 to +20


4).how can I  check the states  of process?


we can execute the command like as the,


top command 


here only we can figure it out .


we have four states are there.


running,sleeping,stopped and zombie


5).How can I check when process was started ?


we can execute the command like asthe ,


ps -ef command . so in this way we can get it the when process was started.


6).How can I check how much cpu and memeory a process is utilizing?


we can execute the top comamnd . so in this way we can figure it out easily 


top it will list out the how much memeory and cpu is consuimng 


so in this way we can figure it out which process is consuming more cpu and more memeory


that's what top comamnd is used in linux os 




---------------------------------------


editor :


1)what is the difference between vi and vim editor in linux os ?


both are editors . snd then strings will be different.


vim and vi command those user's user id's less then 200


2).what are the modes are avilbe into vim editor?


insert mode

command mode

execution mode


3).


How will you copy/delete/edit/lines in vim edirot?


4).How will you replace an string in vim editor?


:%s/select that word which you want to chnage/nandhini/g


5).How to run linux terminal command if you are in vim

editor?


: ! ls /tmp


6).How to compare two files using vim ?


vimdiff /etc/passwd /etc/fstab


so in this way we can caompare the two files using vim edirot


7).How do i search text in vim?


we can execute the command like as the ,


open the an file in linux os 


cat /etc/passwd


bottom of the file , we can type the any word 


/root = so in this way we can find the words into 


/etc/passwd file


8).How to enter into insert mode from command mode in linux so?


press i .so in this way we can enter into insert

mode from command mode in linux os 



9).shdecling inux jobs:


1).How to list corntab entries?


crontab -l command . so in this way we can get the list

of corntab entries.


2).How to list the crontab entries for particular user?


we can execute the comamnd like asthe ,


crontab -lu root

3).How to remove crontab entries from a particular user?


crontab -ru nandhini


so in this way we can execute the crontab entries form

a particular user.


4).How to run multiple commands with single corn?


we can execute the command like asthe ,


crontab -e command 


so open this file .


here type the ,@reboot df -TH &&& ping c 4 8.8.8


so save this file,


at the reboor of you rlinux server , this command is executed at four times.


one command is executed suucessfully and other command is 

executed 


5).what are common strings for cron schdule?

miniture (0-59)

hour(0-23)

day of month(1-31)

month of year(1-12)

day of week 1-6, 0,7 = sunday

then command 


6).How to schedule systemwide corns?



if am going to particular directory called as the ,

cd /etc

then give ls cron command


then it will list out the cron using 


like monthly ,hourly,weekly,yealry

deny ,d

in this way we can figure it out systemwide corns


7).How to enable confirmations with cron?


if you want to get the notifications , we can schedule 


the crons .obviously we can get the confirmations


8).can you schedule  a cron that should run every sunday

12:30 am?


crontab -e command 


here we need to edit like as the,


30 12 * * 0 command 


9).accessing  control lists -control access to files:


1).where do we use chmod and setfacl command in linux os?



chmod command : changing the file permissions 


using this command we can change the file permissions:


so we can execute the command like as the,


chmod 444 filename.1


setfacl -m u:ram:rwx filename



2).How to check if there is an acl implemented on a file?


we can executed the command like as the ,

getfacl filename 


in this way we can get the information's about acl is implements on this file.


3).How to change default attribute of the file?


lsattr username or filename'


it will display the file attribute


we need to execute the vommand like as the


chattr +i filename


now am going to remove the file


rm -rf filename


its shows pertons not permitted


once am going to remove the chattr command on this

'file , now the file will be deleted

4).How to modify access time of a file?


we can execute the command like as the,


touch  --reference /etc/passwd nandhini

5).can i chnage modify time of a file to some

past date?




yes we can change it .


touch --reference /etc/passwd root



6).How to check total number.of disk in linux os?


we can execute the command like as the,


fdisk -l command 


lsblk command


df -Th command



blkid command :


which is used to list out avilable partitions are formatted and 


associated filesystems in linux os.

7).How to check uuid of a disk?



8).what is file is used to mount disk parmaently?


we can execute the command like as the,


vi /etc/fstab command 


9).what is the use of fdisk command in linux os?

it will list out avilibity partitions in the linux os


10).How to create and reduce extend lvm in linux os ?




11).How to check who modified this file?


we can install the aide tool


using this tool we can findout the who midifed this file


next we can execute the command like as the .


ll -l  filename or ls -l filename 



12).what is the command to cheack the file modifications time in linux os ?


we can execute the command like as the ,


ls -l filename 


so in this way we can check it out the file modificatons time in inux os .


13).how will fond the files conating string word?


we can execute the command likea sthe 


grep command


grep -n1 /etc/passwd

grep root /etc/passwd 


14).How do you dealing with mount parttions in linux os?


we can exdcute the command like as the,


findmnt command

cat /proc/mounts


15).How to check on os is running on virtual of physical machine in linux os?


dmidecode | grep -i vm command 


16).How to remove an inode from an linux os ?


17).how do you repair linux partitions in linux os?

18).How to clear a partition in Linux?

To delete a partition using the fdisk utility, you must first log into your system as root or use the sudo command to gain superuser privileges. 

Then, you can run the fdisk command with the appropriate options to delete the desired partition.


19)How do I unmount all partitions in Linux?

sudo mount -av


20).whar are the partions are available in linux os ?


primary 


extened 











Comments

Post a Comment

Popular posts from this blog

Linux interview Questions :

 1).How to recover accidently deleted /etc/fstab into linux os ? anyone deleted this /etc/fstab .after this we can' boot ur os. boot into recovery mode . then go to the linux terminal page . here we have to execute the blkid command  here it will list out the avilble partions and attached filesystems . if your deleting the /etc/fatab.that time root parttion won't be work  now we can mount the root parttion in rw mode mount -t ext4 -0 rw,remount dev/sda1 / 2).VMSTAT command into linux ? 3).iostat and dstat command into linux os ? 4).LInux free command into linux os ? in this way we can check it our the memeory usage and swap memeory as well. then it will display out the , used,space avilble ,total ,buffer/catche abd shared what is free space we can execute the command like as the, free -b command : we will get the particular output for the bits  so if you want to getto int the outpit in kilobytes : so we can execut ethe comamnd like as the, free -k free -g: it will sh...
Read more
 Aws Certification Manager into aws environment: 1).first we need to create the vpc  2).next things we have to create the two public  subnets based on multiple avilibity zones we can craete the multiple subnets . 3).setup the the internet gateway  4).next internet gateway is needed to attach with the  vpc . 5).setup the route table  next am going to associate the all subnets into route tables which we are careted. next am going to add the igw for public subnets routes --------------------------------------------- setup the ec2 instances: while lancing the ec2 server , we have to choose the  vpc and public subnets and added into that. here we need to install the and configure the apache webserver ---------------------------------------- setup the loadbalnacer firsts we need to create the target group and add the ec2 servers. then we can to create the load balancer and add the target group inside it . ---------------------------- we dont want use loadnal...
Read more

SQL Interview Questions:

 SQL Interview Questions: sql interview questions: 1).What is sql? 2).what are the subsets of sql? ddl -dattruncatea definitaion laungade = create ,alter,drop, dml dcl tcl --------------------- 1).create the database : insert,update,delete,select sql for beginners : 1).how to create the table? 2).How to insert the values and rows into the tables? 3).How to update the table into sql? for example am entring the john age is wrong. so i need to chnage the 25 . so for that situvation we have to use the upadte command into sql . so , we can execute the command like as the, update student  set  age =23 where name='john';   4).How to delete the rows from the paticular tables and delete the compeplete table? ------------------------------------------------------ 1).How to create the customer table into sql databases? 1)sql practice questions? 1).How to create the customer table into sql? create table customer (customer_id varchar(200),customer_name varchar(200),customer_addre...
Read more