Linux Interview questions

 1).Linux interview questions:


1).How will you change default userid value in linux os ?


first we can execute the command like as the,


id command 


so in this way we can check it out default userid value


changing the default userid value into linux os:


2).-root # rm -rf /tmp/test gives error operations not permitted ? reason?


3)./etc/hosts (which rpm is responsible for creating this file).


4).what is the difference between rpm and yum ?


5).what is difference between hard and softlink into linux os ?


6).what is sticky bit?


7).How will you check open ports on linux server?


8).How will you check open ports on remote servers(without login)


9).your site is throwing 500 error,how will you start 

troubleshooting it?


10).How will you craete space on disk if it is showing 100% used ?



11).what is package of sar command and what does it do?



How to install the sar command 


yum install sysstsat -y command



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