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SYSTEMD−ANALYZE

NAME

systemd-analyze − Analyze and debug system manager

SYNOPSIS

DESCRIPTION

systemd−analyze may be used to determine system boot−up performance statistics and retrieve other state and tracing information from the system and service manager, and to verify the correctness of unit files. It is also used to access special functions useful for advanced system manager debugging.

If no command is passed, systemd−analyze time is implied.

systemd−analyze time
This command prints the time spent in the kernel before userspace has been reached, the time spent in the 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.

Example 1. Show how long the boot took

# in a container
$ systemd−analyze time
Startup finished in 296ms (userspace)
multi−user.target reached after 275ms in userspace

# on a real machine
$ systemd−analyze time
Startup finished in 2.584s (kernel) + 19.176s (initrd) + 47.847s (userspace) = 1min 9.608s
multi−user.target reached after 47.820s in userspace

systemd−analyze blame
This command 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. Also note: systemd−analyze blame doesn't display results for services with Type=simple, because systemd considers such services to be started immediately, hence no measurement of the initialization delays can be done. Also note that this command only shows the time units took for starting up, it does not show how long unit jobs spent in the execution queue. In particular it shows the time units spent in "activating" state, which is not defined for units such as device units that transition directly from "inactive" to "active". This command hence gives an impression of the performance of program code, but cannot accurately reflect latency introduced by waiting for hardware and similar events.

Example 2. Show which units took the most time during boot

$ systemd−analyze blame
32.875s pmlogger.service
20.905s systemd−networkd−wait−online.service
13.299s dev−vda1.device
...
23ms sysroot.mount
11ms initrd−udevadm−cleanup−db.service
3ms sys−kernel−config.mount

systemd−analyze critical−chain [UNIT...]
This command prints a tree of the time−critical chain of units (for each of the specified UNITs or for the default target otherwise). 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 services might depend on socket activation and because of the parallel execution of units. Also, similarly to the blame command, this only takes into account the time units spent in "activating" state, and hence does not cover units that never went through an "activating" state (such as device units that transition directly from "inactive" to "active"). Moreover it does not show information on jobs (and in particular not jobs that timed out).

Example 3. systemd−analyze critical−chain

$ systemd−analyze critical−chain
multi−user.target @47.820s
└─pmie.service @35.968s +548ms
└─pmcd.service @33.715s +2.247s
└─network−online.target @33.712s
└─systemd−networkd−wait−online.service @12.804s +20.905s
└─systemd−networkd.service @11.109s +1.690s
└─systemd−udevd.service @9.201s +1.904s
└─systemd−tmpfiles−setup−dev.service @7.306s +1.776s
└─kmod−static−nodes.service @6.976s +177ms
└─systemd−journald.socket
└─system.slice
└─−.slice

systemd−analyze dump [pattern...]
Without any parameter, this command outputs a (usually very long) human−readable serialization of the complete service manager state. Optional glob pattern may be specified, causing the output to be limited to units whose names match one of the patterns. The output format is subject to change without notice and should not be parsed by applications. This command is rate limited for unprivileged users.

Example 4. Show the internal state of user manager

$ systemd−analyze −−user dump
Timestamp userspace: Thu 2019−03−14 23:28:07 CET
Timestamp finish: Thu 2019−03−14 23:28:07 CET
Timestamp generators−start: Thu 2019−03−14 23:28:07 CET
Timestamp generators−finish: Thu 2019−03−14 23:28:07 CET
Timestamp units−load−start: Thu 2019−03−14 23:28:07 CET
Timestamp units−load−finish: Thu 2019−03−14 23:28:07 CET
−> Unit proc−timer_list.mount:
Description: /proc/timer_list
...
−> Unit default.target:
Description: Main user target
...

systemd−analyze plot
This command prints either an SVG graphic, detailing which system services have been started at what time, highlighting the time they spent on initialization, or the raw time data in JSON or table format.

Example 5. Plot a bootchart

$ systemd−analyze plot >bootup.svg
$ eog bootup.svg&

systemd−analyze dot [pattern...]
This command generates 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.

Example 6. Plot all dependencies of any unit whose name starts with "avahi−daemon"

$ systemd−analyze dot 'avahi−daemon.*' | dot −Tsvg >avahi.svg
$ eog avahi.svg

Example 7. Plot the dependencies between all known target units

$ systemd−analyze dot −−to−pattern='*.target' −−from−pattern='*.target' \
| dot −Tsvg >targets.svg
$ eog targets.svg

systemd−analyze unit−paths
This command outputs a list of all directories from which unit files, .d overrides, and .wants, .requires symlinks may be loaded. Combine with −−user to retrieve the list for the user manager instance, and −−global for the global configuration of user manager instances.

Example 8. Show all paths for generated units

$ systemd−analyze unit−paths | grep '^/run'
/run/systemd/system.control
/run/systemd/transient
/run/systemd/generator.early
/run/systemd/system
/run/systemd/system.attached
/run/systemd/generator
/run/systemd/generator.late

Note that this verb prints the list that is compiled into systemd−analyze itself, and does not communicate with the running manager. Use

systemctl [−−user] [−−global] show −p UnitPath −−value

to retrieve the actual list that the manager uses, with any empty directories omitted.

systemd−analyze exit−status [STATUS...]
This command prints a list of exit statuses along with their "class", i.e. the source of the definition (one of "glibc", "systemd", "LSB", or "BSD"), see the Process Exit Codes section in systemd.exec(5). If no additional arguments are specified, all known statuses are shown. Otherwise, only the definitions for the specified codes are shown.

Example 9. Show some example exit status names

$ systemd−analyze exit−status 0 1 {63..65}
NAME STATUS CLASS
SUCCESS 0 glibc
FAILURE 1 glibc
− 63 −
USAGE 64 BSD
DATAERR 65 BSD

systemd−analyze capability [CAPABILITY...]
This command prints a list of Linux capabilities along with their numeric IDs. See capabilities(7) for details. If no argument is specified the full list of capabilities known to the service manager and the kernel is shown. Capabilities defined by the kernel but not known to the service manager are shown as "cap_???". Optionally, if arguments are specified they may refer to specific cabilities by name or numeric ID, in which case only the indicated capabilities are shown in the table.

Example 10. Show some example capability names

$ systemd−analyze capability 0 1 {30..32}
NAME NUMBER
cap_chown 0
cap_dac_override 1
cap_audit_control 30
cap_setfcap 31
cap_mac_override 32

systemd−analyze condition CONDITION...
This command will evaluate Condition*=... and Assert*=... assignments, and print their values, and the resulting value of the combined condition set. See systemd.unit(5) for a list of available conditions and asserts.

Example 11. Evaluate conditions that check kernel versions

$ systemd−analyze condition 'ConditionKernelVersion = ! <4.0' \
'ConditionKernelVersion = >=5.1' \
'ConditionACPower=|false' \
'ConditionArchitecture=|!arm' \
'AssertPathExists=/etc/os−release'
test.service: AssertPathExists=/etc/os−release succeeded.
Asserts succeeded.
test.service: ConditionArchitecture=|!arm succeeded.
test.service: ConditionACPower=|false failed.
test.service: ConditionKernelVersion=>=5.1 succeeded.
test.service: ConditionKernelVersion=!<4.0 succeeded.
Conditions succeeded.

systemd−analyze syscall−filter [SET...]
This command will list system calls contained in the specified system call set SET, or all known sets if no sets are specified. Argument SET must include the "@" prefix.

systemd−analyze filesystems [SET...]
This command will list filesystems in the specified filesystem set SET, or all known sets if no sets are specified. Argument SET must include the "@" prefix.

systemd−analyze calendar EXPRESSION...
This command will parse and normalize repetitive calendar time events, and will calculate when they elapse next. This takes the same input as the OnCalendar= setting in systemd.timer(5), following the syntax described in systemd.time(7). By default, only the next time the calendar expression will elapse is shown; use −−iterations= to show the specified number of next times the expression elapses. Each time the expression elapses forms a timestamp, see the timestamp verb below.

Example 12. Show leap days in the near future

$ systemd−analyze calendar −−iterations=5 '*−2−29 0:0:0'
Original form: *−2−29 0:0:0
Normalized form: *−02−29 00:00:00
Next elapse: Sat 2020−02−29 00:00:00 UTC
From now: 11 months 15 days left
Iter. #2: Thu 2024−02−29 00:00:00 UTC
From now: 4 years 11 months left
Iter. #3: Tue 2028−02−29 00:00:00 UTC
From now: 8 years 11 months left
Iter. #4: Sun 2032−02−29 00:00:00 UTC
From now: 12 years 11 months left
Iter. #5: Fri 2036−02−29 00:00:00 UTC
From now: 16 years 11 months left

systemd−analyze timestamp TIMESTAMP...
This command parses a timestamp (i.e. a single point in time) and outputs the normalized form and the difference between this timestamp and now. The timestamp should adhere to the syntax documented in systemd.time(7), section "PARSING TIMESTAMPS".

Example 13. Show parsing of timestamps

$ systemd−analyze timestamp yesterday now tomorrow
Original form: yesterday
Normalized form: Mon 2019−05−20 00:00:00 CEST
(in UTC): Sun 2019−05−19 22:00:00 UTC
UNIX seconds: @15583032000
From now: 1 day 9h ago

Original form: now
Normalized form: Tue 2019−05−21 09:48:39 CEST
(in UTC): Tue 2019−05−21 07:48:39 UTC
UNIX seconds: @1558424919.659757
From now: 43us ago

Original form: tomorrow
Normalized form: Wed 2019−05−22 00:00:00 CEST
(in UTC): Tue 2019−05−21 22:00:00 UTC
UNIX seconds: @15584760000
From now: 14h left

systemd−analyze timespan EXPRESSION...
This command parses a time span (i.e. a difference between two timestamps) and outputs the normalized form and the equivalent value in microseconds. The time span should adhere to the syntax documented in systemd.time(7), section "PARSING TIME SPANS". Values without units are parsed as seconds.

Example 14. Show parsing of timespans

$ systemd−analyze timespan 1s 300s '1year 0.000001s'
Original: 1s
μs: 1000000
Human: 1s

Original: 300s
μs: 300000000
Human: 5min

Original: 1year 0.000001s
μs: 31557600000001
Human: 1y 1us

systemd−analyze cat−config NAME|PATH...
This command is similar to systemctl cat, but operates on config files. It will copy the contents of a config file and any drop−ins to standard output, using the usual systemd set of directories and rules for precedence. Each argument must be either an absolute path including the prefix (such as /etc/systemd/logind.conf or /usr/lib/systemd/logind.conf), or a name relative to the prefix (such as systemd/logind.conf).

Example 15. Showing logind configuration

$ systemd−analyze cat−config systemd/logind.conf
# /etc/systemd/logind.conf
...
[Login]
NAutoVTs=8
...

# /usr/lib/systemd/logind.conf.d/20−test.conf
... some override from another package

# /etc/systemd/logind.conf.d/50−override.conf
... some administrator override

systemd−analyze compare−versions VERSION1 [OP] VERSION2
This command has two distinct modes of operation, depending on whether the operator OP is specified.

In the first mode — when OP is not specified — it will compare the two version strings and print either "VERSION1 < VERSION2", or "VERSION1 == VERSION2", or "VERSION1 > VERSION2" as appropriate.

The exit status is 0 if the versions are equal, 11 if the version of the right is smaller, and 12 if the version of the left is smaller. (This matches the convention used by rpmdev−vercmp.)

In the second mode — when OP is specified — it will compare the two version strings using the operation OP and return 0 (success) if they condition is satisfied, and 1 (failure) otherwise. OP may be lt, le, eq, ne, ge, gt. In this mode, no output is printed. (This matches the convention used by dpkg(1) −−compare−versions.)

Example 16. Compare versions of a package

$ systemd−analyze compare−versions systemd−250~rc1.fc36.aarch64 systemd−251.fc36.aarch64
systemd−250~rc1.fc36.aarch64 < systemd−251.fc36.aarch64
$ echo $?
12

$ systemd−analyze compare−versions 1 lt 2; echo $?
0
$ systemd−analyze compare−versions 1 ge 2; echo $?
1

systemd−analyze verify FILE...
This command will load unit files and print warnings if any errors are detected. Files specified on the command line will be loaded, but also any other units referenced by them. A unit's name on disk can be overridden by specifying an alias after a colon; see below for an example. The full unit search path is formed by combining the directories for all command line arguments, and the usual unit load paths. The variable $SYSTEMD_UNIT_PATH is supported, and may be used to replace or augment the compiled in set of unit load paths; see systemd.unit(5). All units files present in the directories containing the command line arguments will be used in preference to the other paths.

The following errors are currently detected:

• unknown sections and directives,

• missing dependencies which are required to start the given unit,

• man pages listed in Documentation= which are not found in the system,

• commands listed in ExecStart= and similar which are not found in the system or not executable.

Example 17. Misspelt directives

$ cat ./user.slice
[Unit]
WhatIsThis=11
Documentation=man:nosuchfile(1)
Requires=different.service

[Service]
Description=x

$ systemd−analyze verify ./user.slice
[./user.slice:9] Unknown lvalue 'WhatIsThis' in section 'Unit'
[./user.slice:13] Unknown section 'Service'. Ignoring.
Error: org.freedesktop.systemd1.LoadFailed:
Unit different.service failed to load:
No such file or directory.
Failed to create user.slice/start: Invalid argument
user.slice: man nosuchfile(1) command failed with code 16

Example 18. Missing service units

$ tail ./a.socket ./b.socket
==> ./a.socket <==
[Socket]
ListenStream=100

==> ./b.socket <==
[Socket]
ListenStream=100
Accept=yes

$ systemd−analyze verify ./a.socket ./b.socket
Service a.service not loaded, a.socket cannot be started.
Service b@0.service not loaded, b.socket cannot be started.

Example 19. Aliasing a unit

$ cat /tmp/source
[Unit]
Description=Hostname printer

[Service]
Type=simple
ExecStart=/usr/bin/echo %H
MysteryKey=true

$ systemd−analyze verify /tmp/source
Failed to prepare filename /tmp/source: Invalid argument

$ systemd−analyze verify /tmp/source:alias.service
/tmp/systemd−analyze−XXXXXX/alias.service:7: Unknown key name 'MysteryKey' in section 'Service', ignoring.

systemd−analyze security [UNIT...]
This command analyzes the security and sandboxing settings of one or more specified service units. If at least one unit name is specified the security settings of the specified service units are inspected and a detailed analysis is shown. If no unit name is specified, all currently loaded, long−running service units are inspected and a terse table with results shown. The command checks for various security−related service settings, assigning each a numeric "exposure level" value, depending on how important a setting is. It then calculates an overall exposure level for the whole unit, which is an estimation in the range 0.0...10.0 indicating how exposed a service is security−wise. High exposure levels indicate very little applied sandboxing. Low exposure levels indicate tight sandboxing and strongest security restrictions. Note that this only analyzes the per−service security features systemd itself implements. This means that any additional security mechanisms applied by the service code itself are not accounted for. The exposure level determined this way should not be misunderstood: a high exposure level neither means that there is no effective sandboxing applied by the service code itself, nor that the service is actually vulnerable to remote or local attacks. High exposure levels do indicate however that most likely the service might benefit from additional settings applied to them.

Please note that many of the security and sandboxing settings individually can be circumvented — unless combined with others. For example, if a service retains the privilege to establish or undo mount points many of the sandboxing options can be undone by the service code itself. Due to that is essential that each service uses the most comprehensive and strict sandboxing and security settings possible. The tool will take into account some of these combinations and relationships between the settings, but not all. Also note that the security and sandboxing settings analyzed here only apply to the operations executed by the service code itself. If a service has access to an IPC system (such as D−Bus) it might request operations from other services that are not subject to the same restrictions. Any comprehensive security and sandboxing analysis is hence incomplete if the IPC access policy is not validated too.

Example 20. Analyze systemd−logind.service

$ systemd−analyze security −−no−pager systemd−logind.service
NAME DESCRIPTION EXPOSURE
✗ PrivateNetwork= Service has access to the host's network 0.5
✗ User=/DynamicUser= Service runs as root user 0.4
✗ DeviceAllow= Service has no device ACL 0.2
✓ IPAddressDeny= Service blocks all IP address ranges
...
→ Overall exposure level for systemd−logind.service: 4.1 OK 🙂

systemd−analyze inspect−elf FILE...
This command will load the specified files, and if they are ELF objects (executables, libraries, core files, etc.) it will parse the embedded packaging metadata, if any, and print it in a table or json format. See the Packaging Metadata [1] documentation for more information.

Example 21. Table output

$ systemd−analyze inspect−elf −−json=pretty /tmp/core.fsverity.1000.f77dac5dc161402aa44e15b7dd9dcf97.58561.1637106137000000
{
"elfType" : "coredump",
"elfArchitecture" : "AMD x86−64",
"/home/bluca/git/fsverity−utils/fsverity" : {
"type" : "deb",
"name" : "fsverity−utils",
"version" : "1.3−1",
"buildId" : "7c895ecd2a271f93e96268f479fdc3c64a2ec4ee"
},
"/home/bluca/git/fsverity−utils/libfsverity.so.0" : {
"type" : "deb",
"name" : "fsverity−utils",
"version" : "1.3−1",
"buildId" : "b5e428254abf14237b0ae70ed85fffbb98a78f88"
}
}

OPTIONS

The following options are understood:

−−system

Operates on the system systemd instance. This is the implied default.

−−user

Operates on the user systemd instance.

−−global

Operates on the system−wide configuration for user systemd instance.

−−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=, Requisite=, Wants= and Conflicts= are shown. If neither is passed, this shows dependencies of all these types.

−−from−pattern=, −−to−pattern=

When used in conjunction with the dot command (see above), this selects which relationships are shown in the dependency graph. Both options require a glob(7) pattern as an argument, which will be matched against the left−hand and the right−hand, respectively, nodes of a relationship.

Each of these can be used more than once, in which case the unit name must match one of the values. When tests for both sides of the relation are present, a relation must pass both tests to be shown. When patterns are also specified as positional arguments, they must match at least one side of the relation. In other words, patterns specified with those two options will trim the list of edges matched by the positional arguments, if any are given, and fully determine the list of edges shown otherwise.

−−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, e.g. "50ms".

−−man=no

Do not invoke man(1) to verify the existence of man pages listed in Documentation=.

−−generators

Invoke unit generators, see systemd.generator(7). Some generators require root privileges. Under a normal user, running with generators enabled will generally result in some warnings.

−−recursive−errors=MODE

Control verification of units and their dependencies and whether systemd−analyze verify exits with a non−zero process exit status or not. With yes, return a non−zero process exit status when warnings arise during verification of either the specified unit or any of its associated dependencies. With no, return a non−zero process exit status when warnings arise during verification of only the specified unit. With one, return a non−zero process exit status when warnings arise during verification of either the specified unit or its immediate dependencies. If this option is not specified, zero is returned as the exit status regardless whether warnings arise during verification or not.

−−root=PATH

With cat−files and verify, operate on files underneath the specified root path PATH.

−−image=PATH

With cat−files and verify, operate on files inside the specified image path PATH.

−−offline=BOOL

With security, perform an offline security review of the specified unit files, i.e. does not have to rely on PID 1 to acquire security information for the files like the security verb when used by itself does. This means that −−offline= can be used with −−root= and −−image= as well. If a unit's overall exposure level is above that set by −−threshold= (default value is 100), −−offline= will return an error.

−−profile=PATH

With security −−offline=, takes into consideration the specified portable profile when assessing unit settings. The profile can be passed by name, in which case the well−known system locations will be searched, or it can be the full path to a specific drop−in file.

−−threshold=NUMBER

With security, allow the user to set a custom value to compare the overall exposure level with, for the specified unit files. If a unit's overall exposure level, is greater than that set by the user, security will return an error. −−threshold= can be used with −−offline= as well and its default value is 100.

−−security−policy=PATH

With security, allow the user to define a custom set of requirements formatted as a JSON file against which to compare the specified unit file(s) and determine their overall exposure level to security threats.

Table 1. Accepted Assessment Test Identifiers
See example "JSON Policy" below.

−−json=MODE

With the security command, generate a JSON formatted output of the security analysis table. The format is a JSON array with objects containing the following fields: set which indicates if the setting has been enabled or not, name which is what is used to refer to the setting, json_field which is the JSON compatible identifier of the setting, description which is an outline of the setting state, and exposure which is a number in the range 0.0...10.0, where a higher value corresponds to a higher security threat. The JSON version of the table is printed to standard output. The MODE passed to the option can be one of three: off which is the default, pretty and short which respectively output a prettified or shorted JSON version of the security table. With the plot command, genereate a JSON formatted output of the raw time data. The format is a JSON array with objects containing the following fields: name which is the unit name, activated which is the time after startup the service was activated, activating which is how long after startup the service was initially started, time which is how long the service took to activate from when it was initially started, deactivated which is the time after startup that the service was deactivated, deactivating whcih is the time after startup that the service was initially told to deactivate.

−−iterations=NUMBER

When used with the calendar command, show the specified number of iterations the specified calendar expression will elapse next. Defaults to 1.

−−base−time=TIMESTAMP

When used with the calendar command, show next iterations relative to the specified point in time. If not specified defaults to the current time.

−−unit=UNIT

When used with the condition command, evaluate all the Condition*=... and Assert*=... assignments in the specified unit file. The full unit search path is formed by combining the directories for the specified unit with the usual unit load paths. The variable $SYSTEMD_UNIT_PATH is supported, and may be used to replace or augment the compiled in set of unit load paths; see systemd.unit(5). All units files present in the directory containing the specified unit will be used in preference to the other paths.

−−table

When used with the plot command, the raw time data is output in a table.

−−no−legend

When used with the plot command in combination with either −−table or −−json=, no legends or hints are included in the output.

−H, −−host=

Execute the operation remotely. Specify a hostname, or a username and hostname separated by "@", to connect to. The hostname may optionally be suffixed by a port ssh is listening on, separated by ":", and then a container name, separated by "/", which connects directly to a specific container on the specified host. This will use SSH to talk to the remote machine manager instance. Container names may be enumerated with machinectl −H HOST. Put IPv6 addresses in brackets.

−M, −−machine=

Execute operation on a local container. Specify a container name to connect to, optionally prefixed by a user name to connect as and a separating "@" character. If the special string ".host" is used in place of the container name, a connection to the local system is made (which is useful to connect to a specific user's user bus: "−−user −−machine=lennart@.host"). If the "@" syntax is not used, the connection is made as root user. If the "@" syntax is used either the left hand side or the right hand side may be omitted (but not both) in which case the local user name and ".host" are implied.

−−quiet

Suppress hints and other non−essential output.

−h, −−help

Print a short help text and exit.

−−version

Print a short version string and exit.

−−no−pager

Do not pipe output into a pager.

EXIT STATUS

For most commands, 0 is returned on success, and a non−zero failure code otherwise.

With the verb compare−versions, in the two−argument form, 12, 0, 11 is returned if the second version string is respectively larger, equal, or smaller to the first. In the three−argument form, 0 or 1 if the condition is respectively true or false.

ENVIRONMENT

$SYSTEMD_LOG_LEVEL

The maximum log level of emitted messages (messages with a higher log level, i.e. less important ones, will be suppressed). Either one of (in order of decreasing importance) emerg, alert, crit, err, warning, notice, info, debug, or an integer in the range 0...7. See syslog(3) for more information.

$SYSTEMD_LOG_COLOR

A boolean. If true, messages written to the tty will be colored according to priority.

This setting is only useful when messages are written directly to the terminal, because journalctl(1) and other tools that display logs will color messages based on the log level on their own.

$SYSTEMD_LOG_TIME

A boolean. If true, console log messages will be prefixed with a timestamp.

This setting is only useful when messages are written directly to the terminal or a file, because journalctl(1) and other tools that display logs will attach timestamps based on the entry metadata on their own.

$SYSTEMD_LOG_LOCATION

A boolean. If true, messages will be prefixed with a filename and line number in the source code where the message originates.

Note that the log location is often attached as metadata to journal entries anyway. Including it directly in the message text can nevertheless be convenient when debugging programs.

$SYSTEMD_LOG_TID

A boolean. If true, messages will be prefixed with the current numerical thread ID (TID).

Note that the this information is attached as metadata to journal entries anyway. Including it directly in the message text can nevertheless be convenient when debugging programs.

$SYSTEMD_LOG_TARGET

The destination for log messages. One of console (log to the attached tty), console−prefixed (log to the attached tty but with prefixes encoding the log level and "facility", see syslog(3), kmsg (log to the kernel circular log buffer), journal (log to the journal), journal−or−kmsg (log to the journal if available, and to kmsg otherwise), auto (determine the appropriate log target automatically, the default), null (disable log output).

$SYSTEMD_PAGER

Pager to use when −−no−pager is not given; overrides $PAGER. If neither $SYSTEMD_PAGER nor $PAGER are set, a set of well−known pager implementations are tried in turn, including less(1) and more(1), until one is found. If no pager implementation is discovered no pager is invoked. Setting this environment variable to an empty string or the value "cat" is equivalent to passing −−no−pager.

Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER (as well as $PAGER) will be silently ignored.

$SYSTEMD_LESS

Override the options passed to less (by default "FRSXMK").

Users might want to change two options in particular:

K

This option instructs the pager to exit immediately when Ctrl+C is pressed. To allow less to handle Ctrl+C itself to switch back to the pager command prompt, unset this option.

If the value of $SYSTEMD_LESS does not include "K", and the pager that is invoked is less, Ctrl+C will be ignored by the executable, and needs to be handled by the pager.

X

This option instructs the pager to not send termcap initialization and deinitialization strings to the terminal. It is set by default to allow command output to remain visible in the terminal even after the pager exits. Nevertheless, this prevents some pager functionality from working, in particular paged output cannot be scrolled with the mouse.

See less(1) for more discussion.

$SYSTEMD_LESSCHARSET

Override the charset passed to less (by default "utf−8", if the invoking terminal is determined to be UTF−8 compatible).

$SYSTEMD_PAGERSECURE

Takes a boolean argument. When true, the "secure" mode of the pager is enabled; if false, disabled. If $SYSTEMD_PAGERSECURE is not set at all, secure mode is enabled if the effective UID is not the same as the owner of the login session, see geteuid(2) and sd_pid_get_owner_uid(3). In secure mode, LESSSECURE=1 will be set when invoking the pager, and the pager shall disable commands that open or create new files or start new subprocesses. When $SYSTEMD_PAGERSECURE is not set at all, pagers which are not known to implement secure mode will not be used. (Currently only less(1) implements secure mode.)

Note: when commands are invoked with elevated privileges, for example under sudo(8) or pkexec(1), care must be taken to ensure that unintended interactive features are not enabled. "Secure" mode for the pager may be enabled automatically as describe above. Setting SYSTEMD_PAGERSECURE=0 or not removing it from the inherited environment allows the user to invoke arbitrary commands. Note that if the $SYSTEMD_PAGER or $PAGER variables are to be honoured, $SYSTEMD_PAGERSECURE must be set too. It might be reasonable to completely disable the pager using −−no−pager instead.

$SYSTEMD_COLORS

Takes a boolean argument. When true, systemd and related utilities will use colors in their output, otherwise the output will be monochrome. Additionally, the variable can take one of the following special values: "16", "256" to restrict the use of colors to the base 16 or 256 ANSI colors, respectively. This can be specified to override the automatic decision based on $TERM and what the console is connected to.

$SYSTEMD_URLIFY

The value must be a boolean. Controls whether clickable links should be generated in the output for terminal emulators supporting this. This can be specified to override the decision that systemd makes based on $TERM and other conditions.

EXAMPLES

Example 22. JSON Policy

The JSON file passed as a path parameter to −−security−policy= has a top−level JSON object, with keys being the assessment test identifiers mentioned above. The values in the file should be JSON objects with one or more of the following fields: description_na (string), description_good (string), description_bad (string), weight (unsigned integer), and range (unsigned integer). If any of these fields corresponding to a specific id of the unit file is missing from the JSON object, the default built−in field value corresponding to that same id is used for security analysis as default. The weight and range fields are used in determining the overall exposure level of the unit files: the value of each setting is assigned a badness score, which is multiplied by the policy weight and divided by the policy range to determine the overall exposure that the setting implies. The computed badness is summed across all settings in the unit file, normalized to the 1...100 range, and used to determine the overall exposure level of the unit. By allowing users to manipulate these fields, the 'security' verb gives them the option to decide for themself which ids are more important and hence should have a greater effect on the exposure level. A weight of "0" means the setting will not be checked.

{
"PrivateDevices":
{
"description_good": "Service has no access to hardware devices",
"description_bad": "Service potentially has access to hardware devices",
"weight": 1000,
"range": 1
},
"PrivateMounts":
{
"description_good": "Service cannot install system mounts",
"description_bad": "Service may install system mounts",
"weight": 1000,
"range": 1
},
"PrivateNetwork":
{
"description_good": "Service has no access to the host's network",
"description_bad": "Service has access to the host's network",
"weight": 2500,
"range": 1
},
"PrivateTmp":
{
"description_good": "Service has no access to other software's temporary files",
"description_bad": "Service has access to other software's temporary files",
"weight": 1000,
"range": 1
},
"PrivateUsers":
{
"description_good": "Service does not have access to other users",
"description_bad": "Service has access to other users",
"weight": 1000,
"range": 1
}
}

SEE ALSO

systemd(1), systemctl(1)

NOTES

https://systemd.io/COREDUMP_PACKAGE_METADATA/