SYSTEMD-BOOTCHART(1) systemd-bootchart SYSTEMD-BOOTCHART(1)
systemd-bootchart - Boot performance graphing tool
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=/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
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.
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 much
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 /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 size.
-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
For bugs, please contact the author and current maintainer:
Auke Kok <firstname.lastname@example.org>
systemd 229 SYSTEMD-BOOTCHART(1)
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