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ep:labs:03:contents:tasks:ex3 [2020/11/01 11:59] gheorghe.petre2608 [03. [10p] Iotop] |
ep:labs:03:contents:tasks:ex3 [2025/03/17 20:53] (current) radu.mantu [03. [15p] Zip with compression levels] |
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| - | ==== 03. [10p] Iotop ==== | + | ==== 03. [15p] Zip with compression levels ==== |
| - | <note tip> | + | The **zip** command is used for compression and file packaging under Linux/Unix operating system. It provides 10 levels of compression, where: |
| - | **Iotop** is an utility similar to top command, that interfaces with the kernel to provide per-thread/process I/O usage statistics. | + | * **level 0** : provides no compression, only packaging |
| + | * **level 6** : used as default compression level | ||
| + | * **level 9** : provides maximum compression | ||
| - | <code> | + | <code bash> |
| - | Debian/Ubuntu Linux install iotop | + | $ zip -5 file.zip file.txt |
| - | $ sudo apt-get install iotop | + | |
| - | + | ||
| - | How to use iotop command | + | |
| - | $ sudo iotop OR $ iotop | + | |
| </code> | </code> | ||
| - | Supported options by iotop command: | + | === [10p] Task A - Measurements === |
| - | + | Write a script to measure the compression rate and the time required for each level. You have a few large files in the code skeleton but feel free to add more. If you do add new files, make sure that they are not random data! | |
| - | | **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) || | + | |
| - | </note> | + | |
| - | + | ||
| - | === [10p] Task A - Monitoring the behaviour === | + | |
| - | + | ||
| - | * 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 ({{:ep:laboratoare:dummy.sh|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). | + | |
| - | * Hint - [[https://superuser.com/questions/150117/how-to-get-parent-pid-of-a-given-process-in-gnu-linux-from-command-line|How to get parent PID of a given process in GNU/Linux from command line?]] | + | |
| - | + | ||
| - | :!: :!: NON-DEMO TASK | + | |
| - | + | ||
| - | Provide a screenshot in which it shows the iotop with only the active processes and one of them being the running script. Then another screenshot after you succeeded to kill it. | + | |
| - | + | ||
| - | <solution -hidden> | + | |
| - | {{:ep:laboratoare:lab3-ex4.png?600}} | + | |
| - | + | ||
| - | Find PPID from PID: ps -o ppid= -p PID | + | |
| - | Send SIGINT signal: kill -SIGINT PID,PPID | + | === [5p] Task B - Plot === |
| - | </solution> | + | Generate a plot illustrating the compression rate, size decrease, etc. as a function of **zip** compression level. Make sure that your plot is //understandable// (i.e., has labels, a legend, etc.) Make sure to average multiple measurements for each compression level. |
