Linux for Developers
/Intermediate
System Monitoring
Definition
The continuous observation of a Linux system's resource utilization (CPU, RAM, Disk I/O, Network traffic) using tools like `top`, `vmstat`, `iostat`, and `free`.
Explain Like I'm New
Taking the vital signs (heart rate, blood pressure) of the server to make sure it isn't having a heart attack.
Real World Example
A database is responding incredibly slowly, but CPU usage is low. The admin runs `iostat`. The tool reveals that the physical Hard Drive is at 100% capacity trying to read/write data. The admin realizes they need to upgrade to a faster SSD.
Common Use Cases
- •Performance tuning
- •Bottleneck identification
Interview Questions
basic
- What simple command instantly shows you exactly how much total RAM is installed on the server and how much is currently free?
intermediate
- If a Linux server uses 95% of its RAM, but the `free` command shows almost all of it is being used for 'buff/cache', should you be worried?