How would you troubleshoot Linux services?

You are acting as an SRE responsible for Linux-based services in production. Describe how you would handle the following situations: 1. A server reports that the disk is full. Give a step-by-step troubleshooting process, including what commands you would run, what you would check next after each command, what it means if the filesystem is full but you cannot find large files, and how you would identify the process responsible for the disk usage. 2. A backend service is responding slowly. Explain a structured troubleshooting approach, including the monitoring metrics you would inspect, how you would isolate the bottleneck, and common causes of latency at the application, host, network, and dependency layers. 3. Describe several ways to host an application on Linux, such as native installation, containers, and virtual machines. For each option, explain concretely how you would deploy and run the application, as well as the trade-offs.