Unix has a lot of tools that are available at the Sys Admin's disposal to figure out how the system is configured or how is it behaving under load etc all via the command line interface.
The following are the some of very basic interview questions asked about Troubleshooting an issue related to performance, process or network in Unix.
- You are getting a slow response from a machine(ip + port) , how do you figure out what is the issue?
- How to trace a network port to a process id? lsof,pslist
- CPU and memory is high, figure out application is doing?
- How to find out the files that are open by the application, processes etc.?
- How can you find out the traffic going through the port?
- What is netstat? What does netstat tell us?
- Once you killed a process, how do you know how to start the process?
- How to find out shared library by the application?