Linux
All interview questions related to Linux
Which Linux command quickly shows disk usage for all mounted filesystems in a human-readable format?
Why are SSH key pairs generally preferred over passwords for server access?
How do you quickly identify which processes are consuming the most CPU on a Linux server?
What does the cron expression "0 2 * * 1-5" mean, and how would you test a cron job locally?
A server reports high memory usage. What quick checks do you perform to identify the cause?
Explain the meaning of rwx for user, group, and others, and how chmod/chown modify permissions.
Which command would you use to find the largest files/directories consuming disk space in a path?
What does the shebang line do in a script, and what permission is required to run it directly?
How do you check, start, and enable a service with systemd, and where are unit files located?
What do the 1, 5, and 15 minute load averages indicate on Linux, and how do you interpret them relative to CPU cores?
Describe how you would leverage eBPF for deep observability and runtime security in production Linux systems.
One of your production nodes is reporting 100% disk usage and workloads are failing. How do you investigate and resolve this?
One node in your cluster shows 100% CPU usage with context switching spikes. How do you troubleshoot?
On a Linux production node, `df -h` reports the filesystem nearly full, but `du -sh /` shows far less used space. How do you reconcile the discrepancy and free space safely?
A service starts failing with EMFILE errors. Describe how you identify the cause and fix it.
Services on certain VMs show latency spikes correlated with CPU steal time. How do you investigate and mitigate?
A production node repeatedly reboots due to kernel panics under load. Outline your triage and containment steps.
Disk usage looks low, but new files cannot be created and services fail with ENOSPC. How do you confirm inode exhaustion and fix it?