Linux interview questions

 1).what could be the reason non-bootable linux os and server?


2).How to update the kernel version into linux os ?


3).How to recover the corrupted grub into linux os ?



1).boot your computer using a line cd or usb drive


2).get into live cd mode if avilable


3).then go to the terminal


4).then give ls command . it will list oue partitons 


like hdo 


we can check it out the one by one parttions using ls command 


ls hd0 , ls (hd0,msdos1)


is this way we can figure it out which partions filesytem is not weoking 


set the drive as root


setroot = (partion name)


linux /boot/vmlinux-linux root=/dev/sda1

init


then it will show the inird 


they type the command like as the,


initrd /boot/initrd


then we cna type the command like as the ,


.img


here we can intrd and initramfs files also setiup


then boot ur os 


after login we need to install the grub:


grup-install /dev/sda


then reboot ur os 


4).How will you check kernel version of os you are currently running?


5).How can you check ip address of your server which is currently running?


6).How do you check free disk space on your server?


7).How do you manage services on server?


8).How do you check size of directories and file size into linux os ?



du -sh * | sort command 

cat 


9).How do check open ports on linux server ?


10).How do you check cpu usage for a peocess on s server?

11).How do you craete and access mount points?


12).How do you find a file if you don't know the location?



find and loctae command 


we can execute the command like as the,


find -file /etc/fstab

find .file /etc/fstab


find / -name fstab command


before executing the locate command ,


we need to updatedb- its used to refresh the db


then we can execute the command like as the,


locate fstab 


du 


13).How do you check all logged users in linuux server?


we can execute the w comamnd


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