systemd-analyze — Analyze system boot-up performance
systemd-analyze [OPTIONS...] time
systemd-analyze [OPTIONS...] blame
systemd-analyze [OPTIONS...] critical-chain
systemd-analyze [OPTIONS...] plot [> file.svg]
systemd-analyze [OPTIONS...] dot [pattern...]
systemd-analyze may be used to determine system boot-up performance of the current boot.
systemd-analyze time prints the time spent in the kernel before userspace has been reached, the time spent in the initial RAM disk (initrd) before normal system userspace has been reached and the time normal system userspace took to initialize. Note that these measurements simply measure the time passed up to the point where all system services have been spawned, but not necessarily until they fully finished initialization or the disk is idle.
systemd-analyze blame prints a list of all running units, ordered by the time they took to initialize. This information may be used to optimize boot-up times. Note that the output might be misleading as the initialization of one service might be slow simply because it waits for the initialization of another service to complete.
systemd-analyze critical-chain prints a tree of the time critical chain of units. The time after the unit is active or started is printed after the "@" character. The time the unit takes to start is printed after the "+" character. Note that the output might be misleading as the initialization of one service might depend on socket activation and because of the parallel execution of units.
systemd-analyze plot prints an SVG graphic detailing which system services have been started at what time, highlighting the time they spent on initialization.
systemd-analyze dot Generate
textual dependency graph description in dot format for
further processing with the GraphViz
dot(1)
tool. Use a command line like systemd-analyze
dot | dot -Tsvg > systemd.svg to generate a
graphical dependency tree. Unless
--order or --require
is passed the generated graph will show both ordering
and requirement dependencies. Optional pattern
globbing style specifications
(e.g. *.target) may be given at
the end. A unit dependency is included in the graph if
any of these patterns match either the origin or
destination node.
If no command is passed systemd-analyze time is implied.
The following options are understood:
-h, --help¶Prints a short help text and exits.
--user¶Shows performance data of user sessions instead of the system manager.
--order, --require¶When used in
conjunction with the
dot command (see
above), selects which dependencies are
shown in the dependency graph. If
--order is passed
only dependencies of type
After= or
Before= are
shown. If --require
is passed only dependencies of type
Requires=,
RequiresOverridable=,
Requisite=,
RequisiteOverridable=,
Wants= and
Conflicts= are
shown. If neither is passed, shows
dependencies of all these
types.
--from-pattern=, --to-pattern=¶When used in conjunction with the dot command (see above), selects which relationships are shown in the dependency graph. They both require glob(7) patterns as arguments, which are matched against lefthand and righthand, respectively, nodes of a relationship. Each of these can be used more than once which means a unit name must match one of given values.
--fuzz=timespan¶When used in conjunction
with the critical-chain
command (see above), also show units, which
finished timespan earlier, than the
latest unit in the same level. The unit of
timespan is seconds
unless specified with a different unit,
i.e. "50ms".
This plots all dependencies of any unit whose
name starts with "avahi-daemon.":
$ systemd-analyze dot 'avahi-daemon.*' | dot -Tsvg > avahi.svg $ eog avahi.svg
This plots the dependencies between all known target units:
systemd-analyze dot --to-pattern='*.target' --from-patter='*.target' | dot -Tsvg > targets.svg $ eog targets.svg