A recruiter contacted me via LinkedIn. He was super nice.

The interviewer was not professional. The interview was about system administration and scripting. He focused on one subject, which was bad. If you don't have experience in that specific subject, you will fail.

Overall:

The recruiter was great; he really cared about me succeeding in the interview. He did his job right.

The interviewer was not professional and was not responsive. He did not give hints.

First phase questions specific about the kernel:

He expected me to know about the kernel in depth, which is not possible if you are not working in that field. By the way, I had an interview with the team lead of this role before this interview to ask questions about the role. He did not mention anything about the kernel. So...?

Second phase scripting:

He expected me to remember Linux commands with their flags, which is not possible to do without using man pages or at least the terminal.

The interview went on using Google Docs, which may work for coding but not for Linux, that's for sure.

Kernel-related questions

Write a script to print the biggest path in Linux.

Questions about server power issues: If you have a server that is not powering on, what are the potential problems?

Script to find the biggest CPU percentage, send an email, and then find the biggest NFS path and send another email.