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