systemd-bootchart is a tool, usually run at system startup, that
collects the CPU load, disk load, memory usage, as well as
per-process information from a running system. Collected results are
output as an SVG graph. Normally, systemd-bootchart is invoked by the
kernel by passing init=/usr/lib/systemd/systemd-bootchart on the
kernel command line. systemd-bootchart will then fork the real init
off to resume normal system startup, while monitoring and logging
startup information in the background.
After collecting a certain amount of data (usually 15–30 seconds,
default 20 s) the logging stops and a graph is generated from the
logged information. This graph contains vital clues as to which
resources are being used, in which order, and where possible problems
exist in the startup sequence of the system. It is essentially a more
detailed version of the systemd-analyze plot function.
Of course, bootchart can also be used at any moment in time to
collect and graph some data for an amount of time. It is recommended
to use the --rel switch in this case.
Bootchart does not require root privileges, and will happily run as a
Bootchart graphs are by default written time-stamped in /run/log and
saved to the journal with
MESSAGE_ID=9f26aa562cf440c2b16c773d0479b518. Journal field BOOTCHART=
contains the bootchart in SVG format.
systemd-bootchart can be invoked in several different ways:
The kernel can invoke systemd-bootchart instead of the init
process. In turn, systemd-bootchart will invoke
Started as a standalone program
One can execute systemd-bootchart as normal application from the
command line. In this mode, it is highly recommended to pass the
-r flag in order to not graph the time elapsed since boot and
before systemd-bootchart was started, as it may result in
extremely large graphs. The time elapsed since boot might also
include any time that the system was suspended.
These options can also be set in the /etc/systemd/bootchart.conf
file. See bootchart.conf(5).
Print a short help text and exit.
-n, --sample N
Specify the number of samples, N, to record. Samples will be
recorded at intervals defined with --freq.
-f, --freq f
Specify the sample log frequency, a positive real f, in Hz. Most
systems can cope with values up to 25–50 without creating too
Use relative times instead of absolute times. This is useful for
using bootchart at post-boot time to profile an already booted
system. Without this option the graph would become extremely
large. If set, the horizontal axis starts at the first recorded
sample instead of time 0.0.
Disable filtering of tasks that did not contribute significantly
to the boot. Processes that are too short-lived (only seen in one
sample) or that do not consume any significant CPU time (less
than 0.001 s) will not be displayed in the output graph.
Display the full command line with arguments of processes,
instead of only the process name.
Display process control group
-o, --output path
Specify the output directory for the graphs. By default,
bootchart writes the graphs to /run/log.
-i, --init path
Use this init binary. Defaults to /usr/lib/systemd/systemd.
Enable logging and graphing of processes' PSS (Proportional Set
Size) memory consumption. See filesystems/proc.txt in the kernel
documentation for an explanation of this field.
Enable logging and graphing of the kernel random entropy pool
-x, --scale-x N
Horizontal scaling factor for all variable graph components.
-y, --scale-y N
Vertical scaling factor for all variable graph components.
systemd-bootchart generates SVG graphs. In order to render those on a
graphical display any SVG capable viewer can be used. It should be
noted that the SVG render engines in most browsers (including Chrome
and Firefox) are many times faster than dedicated graphical
applications like Gimp and Inkscape. Just point your browser at
This version of bootchart was implemented from scratch, but is
inspired by former bootchart incantations:
The original bash/shell code implemented bootchart. This version
created a compressed tarball for processing with external
applications. This version did not graph anything, only generated
Ubuntu C Implementation
This version replaced the shell version with a fast and efficient
data logger, but also did not graph the data.
This was the original graphing application for charting the data,
written in java.
pybootchart created a graph from the data collected by either the
bash or C version.
The version of bootchart you are using now combines both the data
collection and the charting into a single application, making it more
efficient and simpler. There are no longer any timing issues with the
data collector and the grapher, as the graphing cannot be run until
the data has been collected. Also, the data kept in memory is reduced
to the absolute minimum needed.
systemd-bootchart does not get the model information for the hard
drive unless the root device is specified with root=/dev/sdxY. Using
UUIDs or PARTUUIDs will boot fine, but the hard drive model will not
be added to the chart.
For bugs, please contact the author and current maintainer:
Auke Kok <firstname.lastname@example.org>
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2016-09-01. If you dis‐
cover any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
systemd 228 SYSTEMD-BOOTCHART(1)