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03. [10p] Iotop
Good to know
Iotop is an utility similar to top command, that interfaces with the kernel to provide per-thread/process I/O usage statistics.
Debian/Ubuntu Linux install iotop $ sudo apt-get install iotop How to use iotop command $ sudo iotop OR $ iotop
Supported options by iotop command:
| Options | Description | |
| –version | show program’s version number and exit | |
| -h, –help | show this help message and exit | |
| -o, –only | only show processes or threads actually doing I/O | |
| -b, –batch | non-interactive mode | |
| -n NUM, –iter=NUM | number of iterations before ending [infinite] | |
| -d SEC, –delay=SEC | delay between iterations [1 second] | |
| -p PID, –pid=PID | processes/threads to monitor [all] | |
| -u USER, –user=USER | users to monitor [all] | |
| -P, –processes | only show processes, not all threads | |
| -a, –accumulated | show accumulated I/O instead of bandwidth | |
| -k, –kilobytes | use kilobytes instead of a human friendly unit | |
| -t, –time | add a timestamp on each line (implies –batch) | |
| -q, –quiet | suppress some lines of header (implies –batch) | |
Monitoring the behaviour
Datafile: dummy.sh.
- Run iotop (install it if you do not already have it) in a separate shell showing only processes or threads actually doing I/O.
- Inspect the script code (dummy.sh) to see what it does.
- Monitor the behaviour of the system with iotop while running the script.
- Identify the PID and PPID of the process running the dummy script and kill the process using command line from another shell (sending SIGINT signal to both parent & child processes).
