Essential Linux Ops & Cloud Engineer Interview Questions Revealed

As a Linux operations engineer, entering a large company can be a pivotal career step; this article shares a collection of interview questions and experiences from a recent Sina Linux ops and cloud engineer interview.

Basic Knowledge

Explain the output of the following commands:

echo "sinaops" | read a ; echo $a

echo "sinaops" | while read a ;do echo $a ;done

What is a Linux daemon process and how does it differ from a regular process?

When using the free command, what do the "buffer" and "cache" fields represent?

What are the inode and block effects of using ln -s /usr/afile /etc/bfile followed by mv /etc/afile /etc/bfile?

What are the differences between the Apache and Nginx web servers?

Which cluster software have you used?

Network Technology

Describe the TCP three‑way handshake process.

Explain the purpose of HTTP keep‑alive and its typical use cases.

Interpret the following HTTP response headers:

Date: Tue,22Feb 2011 04:37:45 GMT

Server: Apache

Last-Modified: Thu,04 Nov 2010 04;12:24 GMT

Etag: "9fc-10c-82-5d73fa00"

Content-Length: 130

Cache-Control: max-age=2592000

Expires: Thu,24 Mar 2011 04:37:45 GMT

Age: 21190

X-Cache: HIT from 86-74.ul.sinaimg.cn

Via: 1.0.86-74.ul.sinaimg.cn:80 (squid/2.6.STABLE21)

Connection: keep-alive

Explain the implementation principles and differences between sessions and cookies.

When LVS is configured in DR mode but real servers respond directly, how would you locate the problem?

Explain the meaning of the following kernel parameters:

net.ipv4.tcp_tw_recycle=1

net.ipv4.tcp_tw_reuse=1

vm.swappiness=0

How do you identify performance bottlenecks on a Linux system? List common monitoring commands and useful options.

Development Skills

Print "hello sina" using as many different programming languages as possible.

In a Bash shell, what do the variables $0, $?, and $$ represent?

Write a script that counts TCP connections on the host and categorizes them by state.

Given a file containing lines like 1 test.sina.com.cn, extract the hostname part preceding ".sina.com.cn" and write it back to the file.

Ensure that only one instance of a script runs at any time (any language).

Calculate the number of days from your birthday to today (any language except Bash).

Write a program to determine whether a given string is a palindrome (any language except Bash).

From a file containing 5,000 random integers between 1 and 100,000 formatted as 100,50,35,89,…, extract the maximum and minimum values (any language except Bash).