sargraph

Copyright (c) 2019-2026 Antmicro

This is a simple python tool that uses "sysstat" ("sar") to save information on CPU, RAM and disk usage. The process runs in background and can be controlled with a set of sargraph sub-commands.

The tool can use "gnuplot" to optionally plot the data it collected. Supported plot formats are PNG, SVG and ASCII, they are determined by filename extensions.

Install requirements

The sargraph requires gnuplot, sysstat (sar), python3 and coreutils to operate. In Debian you can install them with:

# install system dependencies
apt-get update
apt-get install -qqy --no-install-recommends \
    coreutils \
    git \
    gnuplot-nox \
    python3 \
    python3-pip \
    sysstat

# install Python dependencies
pip3 install -r requirements.txt

For rendering HTML plots, you additionally have to install:

pip3 install git+https://github.com/antmicro/servis#egg=servis[bokeh]

Example graph

Usage

All sargraph commands use the following pattern:

$ ./sargraph.py [session_name] [command] [args...]

Let's create a sample disk on which we will run stress tests:

dd if=/dev/zero of=sample_disk.ext4 bs=1M count=130
mkfs.ext4 sample_disk.ext4
mkdir -p ./mountpoint && mount sample_disk.ext4 ./mountpoint

For the purpose of stress tests let's install stress:

apt-get install stress

Starting a session

Start a background session and name it example:

./sargraph.py example start -m ./mountpoint

The data will be saved in example.txt. Logs from screen will be written to example.log.

-m flag allows to specify a chosen filesystem/mountpoint.

Adding a label

Add labels that will be placed as comments in the collected dataset. They will be also visible on the plots:

./sargraph.py example label "Compilation start"

After this, let's simulate some processing:

pushd ./mountpoint
stress -c 16 -i 1 -m 1 --vm-bytes 512M -d 1 --hdd-bytes 70M -t 160s
popd

Plotting a running session

It is possible to plot data collected so far in a still running session:

# Save plot to SVG
./sargraph.py example save plot.svg
# Save plot to PNG
./sargraph.py example save plot.png
# Save plot to ASCII that can be printed in terminal
./sargraph.py example save plot.ascii
# Save plot to interactive HTML plot
./sargraph.py example save plot.html

The supported formats are:

• png format
• svg format
• html format
• ascii format - plot is rendered to text file that can be displayed in terminal

Stopping a session

Stop a session and create a final plot.png plot file if no other plot was created so far:

./sargraph.py example stop

The filename of the final plot can be changed if its placed after the stop command. If the name is none then no plot will be created.

Plotting a closed session

Plot data collected in a session that is not running anymore.

./sargraph.py example plot plot.ascii

The command requires the example.txt log file to be present in the working directory.