homectl, systemd-homed-firstboot.service — Create, remove, change or inspect home directories
homectl [OPTIONS...] {COMMAND} [NAME...]
homectl may be used to create, remove, change or inspect a user's home directory. It's primarily a command interfacing with systemd-homed.service(8) which manages home directories of users.
Home directories managed by systemd-homed.service are self-contained, and thus
include the user's full metadata record in the home's data storage itself, making them easy to migrate
between machines. In particular, a home directory describes a matching user record, and every user record
managed by systemd-homed.service also implies existence and encapsulation of a home
directory. The user account and home directory become the same concept.
The following backing storage mechanisms are supported:
An individual LUKS2 encrypted loopback file for a user, stored in
/home/*.home. At login the file system contained in this files is mounted, after
the LUKS2 encrypted volume has been attached. The user's password is identical to the encryption
passphrase of the LUKS2 volume. Access to data without preceding user authentication is thus not
possible, even for the system administrator. This storage mechanism provides the strongest data
security and is thus recommended.
Similar, but the LUKS2 encrypted file system is located on regular block device, such as a USB storage stick. In this mode home directories and all data they include are nicely migratable between machines, simply by plugging the USB stick into different systems at different times.
An encrypted directory using "fscrypt" on file systems that support it
(at the moment this is primarily "ext4"), located in
/home/*.homedir. This mechanism also provides encryption, but substantially
weaker than LUKS2, as most file system metadata is unprotected. Moreover
it currently does not support changing user passwords once the home directory has been
created.
A "btrfs" subvolume for each user, also located in
/home/*.homedir. This provides no encryption, but good quota
support.
A regular directory for each user, also located in
/home/*.homedir. This provides no encryption, but is a suitable fallback
available on all machines, even where LUKS2, "fscrypt" or "btrfs"
support is not available.
An individual Windows file share (CIFS) for each user.
Note that systemd-homed.service and homectl will not manage
"classic" UNIX user accounts as created with useradd(8) or
similar tools. In particular, this functionality is not suitable for managing system users (i.e. users
with a UID below 1000) but is exclusive to regular ("human") users.
Note that users/home directories managed via systemd-homed.service do not show
up in /etc/passwd and similar files, they are synthesized via glibc NSS during
runtime. They are thus resolvable and may be enumerated via the getent(1)
tool.
This tool interfaces directly with systemd-homed.service, and may execute
specific commands on the home directories it manages. Since every home directory managed that way also
defines a JSON user and group record these home directories may also be inspected and enumerated via
userdbctl(1).
Home directories managed by systemd-homed.service are usually in one of two
states, or in a transition state between them: when "active" they are unlocked and
mounted, and thus accessible to the system and its programs; when "inactive" they are
not mounted and thus not accessible. Activation happens automatically at login of the user and usually
can only complete after a password (or other authentication token) has been supplied. Deactivation
happens after the user fully logged out. A home directory remains active as long as the user is logged in
at least once, i.e. has at least one login session. When the user logs in a second time simultaneously
the home directory remains active. It is deactivated only after the last of the user's sessions
ends.
The following general options are understood (further options that control the various properties
of user records managed by systemd-homed.service are documented further
down):
--identity=FILE¶Read the user's JSON record from the specified file. If passed as
"-" read the user record from standard input. The supplied JSON object must follow
the structure documented in JSON User Records.
This option may be used in conjunction with the create and
update commands (see below), where it allows configuring the user record in JSON
as-is, instead of setting the individual user record properties (see below).
--json=FORMAT, -j¶Controls whether to output the user record in JSON format, if the
inspect command (see below) is used. Takes one of "pretty",
"short" or "off". If "pretty" human-friendly
whitespace and newlines are inserted in the output to make the JSON data more readable. If
"short" all superfluous whitespace is suppressed. If "off" (the
default) the user information is not shown in JSON format but in a friendly human readable formatting
instead. The -j option picks "pretty" when run interactively and
"short" otherwise.
--export-format=FORMAT, -E, -EE¶When used with the inspect verb in JSON mode (see above) may be
used to suppress certain aspects of the JSON user record on output. Specifically, if
"stripped" format is used the binding and runtime fields of the record are
removed. If "minimal" format is used the cryptographic signature is removed too. If
"full" format is used the full JSON record is shown (this is the default). This
option is useful for copying an existing user record to a different system in order to create a
similar user there with the same settings. Specifically: homectl inspect -EE | ssh
root@othersystem homectl create -i- may be used as simple command line for replicating a
user on another host. -E is equivalent to -j --export-format=stripped,
-EE to -j --export-format=minimal. Note that when replicating user
accounts user records acquired in "stripped" mode will retain the original
cryptographic signatures and thus may only be modified when the private key to update them is available
on the destination machine. When replicating users in "minimal" mode, the signature
is removed during the replication and thus the record will be implicitly signed with the key of the destination
machine and may be updated there without any private key replication.
--offline¶Do not attempt to update the copy of the user record and blob directory that is embedded inside of the home area. This allows for operation on home areas that are absent, or without needing to authenticate as the user being modified.
-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.
--no-pager¶Do not pipe output into a pager.
--no-legend¶Do not print the legend, i.e. column headers and the footer with hints.
--no-ask-password¶Do not query the user for authentication for privileged operations.
-h, --help¶--version¶The following options control various properties of the user records/home directories that
systemd-homed.service manages. These switches may be used in conjunction with the
create and update commands for configuring various aspects of the
home directory and the user account:
--real-name=NAME, -c NAME¶The real name for the user. This corresponds with the GECOS field on classic UNIX NSS records.
--realm=REALM¶The realm for the user. The realm associates a user with a specific organization or installation, and allows distinguishing users of the same name defined in different contexts. The realm can be any string that also qualifies as valid DNS domain name, and it is recommended to use the organization's or installation's domain name for this purpose, but this is not enforced nor required. On each system only a single user of the same name may exist, and if a user with the same name and realm is seen it is assumed to refer to the same user while a user with the same name but different realm is considered a different user. Note that this means that two users sharing the same name but with distinct realms are not allowed on the same system. Assigning a realm to a user is optional.
--email-address=EMAIL¶Takes an electronic mail address to associate with the user. On log-in the
$EMAIL environment variable is initialized from this value.
--location=TEXT¶Takes location specification for this user. This is free-form text, which might or
might not be usable by geo-location applications. Example: --location="Berlin,
Germany" or --location="Basement, Room 3a"
--icon-name=ICON¶Takes an icon name to associate with the user, following the scheme defined by the Icon Naming Specification.
--home-dir=PATH, -dPATH¶Takes a path to use as home directory for the user. Note that this is the directory
the user's home directory is mounted to while the user is logged in. This is not where the user's
data is actually stored, see --image-path= for that. If not specified defaults to
/home/$USER.
--uid=UID¶Takes a preferred numeric UNIX UID to assign this user. If a user is to be created with the specified UID and it is already taken by a different user on the local system then creation of the home directory is refused. Note though, if after creating the home directory it is used on a different system and the configured UID is taken by another user there, then systemd-homed may assign the user a different UID on that system. The specified UID must be outside of the system user range. It is recommended to use the 60001…60513 UID range for this purpose. If not specified, the UID is automatically picked. If the home directory is found to be owned by a different UID when logging in, the home directory and everything underneath it will have its ownership changed automatically before login completes.
Note that changing this option for existing home directories generally has no effect on home directories that already have been registered locally (have a local binding), as the UID used for an account on the local system is determined when the home directory is first activated on it, and then remains in effect until the home directory is removed.
Note that users managed by systemd-homed always have a matching group associated with the same name as well as a GID matching the UID of the user. Thus, configuring the GID separately is not permitted.
--member-of=GROUP, -G GROUP¶Takes a comma-separated list of auxiliary UNIX groups this user shall belong
to. Example: --member-of=wheel to provide the user with administrator
privileges. Note that systemd-homed does not manage any groups besides a group
matching the user in name and numeric UID/GID. Thus any groups listed here must be registered
independently, for example with groupadd(8).
Any non-existent groups are ignored. This option may be used more than once, in which case all
specified group lists are combined. If the user is currently a member of a group which is not listed,
the user will be removed from the group.
--capability-bounding-set=CAPABILITIES, --capability-ambient-set=CAPABILITIES¶These options take a space separated list of process capabilities
(e.g. CAP_WAKE_ALARM, CAP_BLOCK_SUSPEND, …) that shall be
set in the capability bounding and ambient sets for all the user's sessions. See capabilities(7)
for details on the capabilities concept. These options may be used more than once, in which case the
specified lists are combined. If the parameter begins with a "~" character the
effect is inverted: the specified capability is dropped from the specific set.
--skel=PATH¶Takes a file system path to a directory. Specifies the skeleton directory to
initialize the home directory with. All files and directories in the specified path are copied into
any newly create home directory. If not specified defaults to /etc/skel/.
--shell=SHELL¶Takes a file system path. Specifies the shell binary to execute on terminal
logins. If not specified defaults to /bin/bash.
--setenv=VARIABLE[=VALUE]¶Takes an environment variable assignment to set for all user processes. May be used
multiple times to set multiple environment variables. When "=" and
VALUE are omitted, the value of the variable with the same name in the
program environment will be used.
Note that a number of other settings also result in environment variables to be set for the
user, including --email=, --timezone= and
--language=.
--timezone=TIMEZONE¶Takes a time zone location name that sets the timezone for the specified user. When
the user logs in the $TZ environment variable is initialized from this
setting. Example: --timezone=Europe/Amsterdam will result in the environment
variable "TZ=:Europe/Amsterdam". (":" is used intentionally as part
of the timezone specification, see
tzset(3).)
--language=LANG¶Takes a comma- or colon-separated list of languages preferred by the user, ordered
by descending priority. The $LANG and $LANGUAGE environment
variables are initialized from this value on login, and thus values suitable for these environment
variables are accepted here, for example --language=de_DE.UTF-8. This option may
be used more than once, in which case the language lists are concatenated.
Either takes a SSH authorized key line to associate with the user record or a
"@" character followed by a path to a file to read one or more such lines from. SSH
keys configured this way are made available to SSH to permit access to this home directory and user
record. This option may be used more than once to configure multiple SSH keys.
--pkcs11-token-uri=URI¶Takes an RFC 7512 PKCS#11 URI referencing a security token (e.g. YubiKey or PIV smartcard) that shall be able to unlock the user account. The security token URI should reference a security token with exactly one pair of X.509 certificate and private key. A random secret key is then generated, encrypted with the public key of the X.509 certificate, and stored as part of the user record. At login time it is decrypted with the PKCS#11 module and then used to unlock the account and associated resources. See below for an example how to set up authentication with a security token.
Instead of a valid PKCS#11 URI, the special strings "list" and
"auto" may be specified. If "list" is passed, a brief table of
suitable, currently plugged in PKCS#11 hardware tokens is shown, along with their URIs. If
"auto" is passed, a suitable PKCS#11 hardware token is automatically selected (this
operation will fail if there isn't exactly one suitable token discovered). The latter is a useful
shortcut for the most common case where a single PKCS#11 hardware token is plugged in.
Note that many hardware security tokens implement both PKCS#11/PIV and FIDO2 with the
"hmac-secret" extension (for example: the YubiKey 5 series), as supported with the
--fido2-device= option below. Both mechanisms are similarly powerful, though FIDO2
is the more modern technology. PKCS#11/PIV tokens have the benefit of being recognizable before
authentication and hence can be used for implying the user identity to use for logging in, which
FIDO2 does not allow. PKCS#11/PIV devices generally require initialization (i.e. storing a
private/public key pair on them, see example below) before they can be used; FIDO2 security tokens
generally do not required that, and work out of the box.
--fido2-credential-algorithm=STRING¶Specify COSE algorithm used in credential generation. The default value is
"es256". Supported values are "es256", "rs256"
and "eddsa".
"es256" denotes ECDSA over NIST P-256 with SHA-256. "rs256"
denotes 2048-bit RSA with PKCS#1.5 padding and SHA-256. "eddsa" denotes
EDDSA over Curve25519 with SHA-512.
Note that your authenticator may choose not to support some algorithms.
--fido2-device=PATH¶Takes a path to a Linux "hidraw" device
(e.g. /dev/hidraw1), referring to a FIDO2 security token implementing the
"hmac-secret" extension that shall be able to unlock the user account. A random salt
value is generated on the host and passed to the FIDO2 device, which calculates a HMAC hash of the
salt using an internal secret key. The result is then used as the key to unlock the user account. The
random salt is included in the user record, so that whenever authentication is needed it can be
passed to the FIDO2 token again.
Instead of a valid path to a FIDO2 "hidraw" device the special strings
"list" and "auto" may be specified. If "list" is
passed, a brief table of suitable discovered FIDO2 devices is shown. If "auto" is
passed, a suitable FIDO2 token is automatically selected, if exactly one is discovered. The latter is
a useful shortcut for the most common case where a single FIDO2 hardware token is plugged in.
Note that FIDO2 devices suitable for this option must implement the
"hmac-secret" extension. Most current devices (such as the YubiKey 5 series) do. If
the extension is not implemented the device cannot be used for unlocking home directories.
The FIDO2 device may be subsequently removed by setting the device path to an empty string (e.g. homectl update $USER --fido2-device="").
Note that many hardware security tokens implement both FIDO2 and PKCS#11/PIV (and thus may be
used with either --fido2-device= or --pkcs11-token-uri=), for a
discussion see above.
--fido2-with-client-pin=BOOL¶When enrolling a FIDO2 security token, controls whether to require the user to enter
a PIN when unlocking the account (the FIDO2 "clientPin" feature). Defaults to
"yes". (Note: this setting is without effect if the security token does not support
the "clientPin" feature at all, or does not allow enabling or disabling
it.)
--fido2-with-user-presence=BOOL¶When enrolling a FIDO2 security token, controls whether to require the user to
verify presence (tap the token, the FIDO2 "up" feature) when unlocking the account.
Defaults to "yes". (Note: this setting is without effect if the security token does not support
the "up" feature at all, or does not allow enabling or disabling it.)
--fido2-with-user-verification=BOOL¶When enrolling a FIDO2 security token, controls whether to require user verification
when unlocking the account (the FIDO2 "uv" feature). Defaults to
"no". (Note: this setting is without effect if the security token does not support
the "uv" feature at all, or does not allow enabling or disabling it.)
--recovery-key=BOOL¶Accepts a boolean argument. If enabled a recovery key is configured for the account. A recovery key is a computer generated access key that may be used to regain access to an account if the password has been forgotten or the authentication token lost. The key is generated and shown on screen, and should be printed or otherwise transferred to a secure location. A recovery key may be entered instead of a regular password to unlock the account.
--blob=PATH, -b PATH, --blob=FILENAME=PATH, -b FILENAME=PATH¶Accepts either a directory path, or a file name followed by a file path. If just a directory path is specified, then the user's entire blob directory is replaced the specified path. Note that this replacement is performed before per-file manipulations are applied, which means these per-file manipulations will be applied on top of the specified directory. If a filename and file path are specified, then the single specified blob file will be overwritten with the specified path. If completely blank, the entire blob directory is emptied out (which also resets all previous blob-related flags up to this point). If a filename is specified but the corresponding path is blank, that single file will be deleted from the blob directory. All changes are performed in temporary copies of the specified files in directories, which means that the originals specified on the command line are not modified. See User Record Blob Directories for more information about blob directories.
--avatar=PATH, --login-background=PATH¶Accept a file path. If set, the specified file is used to overwrite the
corresponding file in the user's blob directory. If blank, the corresponding file is deleted
from the blob directory. Essentially, these options are shortcuts to
--blob=
for the known filenames defined in
User Record Blob Directories.FILENAME=PATH
--locked=BOOLEAN¶Takes a boolean argument. Specifies whether this user account shall be locked. If true logins into this account are prohibited, if false (the default) they are permitted (of course, only if authorization otherwise succeeds).
--not-before=TIMESTAMP, --not-after=TIMESTAMP¶These options take a timestamp string, in the format documented in systemd.time(7) and configures points in time before and after logins into this account are not permitted.
--rate-limit-interval=SECS, --rate-limit-burst=NUMBER¶Configures a rate limit on authentication attempts for this user. If the user attempts to authenticate more often than the specified number, on a specific system, within the specified time interval authentication is refused until the time interval passes. Defaults to 10 times per 1min.
--password-hint=TEXT¶Takes a password hint to store alongside the user record. This string is stored
accessible only to privileged users and the user itself and may not be queried by other users.
Example: --password-hint="My first pet's name".
--enforce-password-policy=BOOL, -P¶Takes a boolean argument. Configures whether to enforce the system's password policy
for this user, regarding quality and strength of selected passwords. Defaults to
on. -P is short for
--enforce-password-policy=no.
--password-change-now=BOOL¶Takes a boolean argument. If true the user is asked to change their password on next login.
--password-change-min=TIME, --password-change-max=TIME, --password-change-warn=TIME, --password-change-inactive=TIME¶Each of these options takes a time span specification as argument (in the syntax
documented in
systemd.time(7)) and
configures various aspects of the user's password expiration policy. Specifically,
--password-change-min= configures how much time has to pass after changing the
password of the user until the password may be changed again. If the user tries to change their
password before this time passes the attempt is refused. --password-change-max=
configures how soon after it has been changed the password expires and needs to be changed again.
After this time passes logging in may only proceed after the password is changed.
--password-change-warn= specifies how much earlier than then the time configured
with --password-change-max= the user is warned at login to change their password as
it will expire soon. Finally --password-change-inactive= configures the time which
has to pass after the password as expired until the user is not permitted to log in or change the
password anymore. Note that these options only apply to password authentication, and do not apply to
other forms of authentication, for example PKCS#11-based security token
authentication.
--disk-size=BYTES¶Either takes a size in bytes as argument (possibly using the usual K, M, G, …
suffixes for 1024 base values), a percentage value, or the special strings "min" or
"max", and configures the disk space to assign to the user. If a percentage value is
specified (i.e. the argument suffixed with "%") it is taken relative to the
available disk space of the backing file system. If specified as "min" assigns the
minimal disk space permitted by the constraints of the backing file system and other limits, when
specified as "max" assigns the maximum disk space available. If the LUKS2 backend is
used this configures the size of the loopback file and file system contained therein. For the other
storage backends configures disk quota using the filesystem's native quota logic, if available. If
not specified, defaults to 85% of the available disk space for the LUKS2 backend and to no quota for
the others.
--access-mode=MODE¶Takes a UNIX file access mode written in octal. Configures the access mode of the
home directory itself. Note that this is only used when the directory is first created, and the user
may change this any time afterwards. Example:
--access-mode=0700
--umask=MASK¶Takes the access mode mask (in octal syntax) to apply to newly created files and directories of the user ("umask"). If set this controls the initial umask set for all login sessions of the user, possibly overriding the system's defaults.
--nice=NICE¶Takes the numeric scheduling priority ("nice level") to apply to the processes of the user at login time. Takes a numeric value in the range -20 (highest priority) to 19 (lowest priority).
--rlimit=LIMIT=VALUE[:VALUE]¶Allows configuration of resource limits for processes of this user, see getrlimit(2)
for details. Takes a resource limit name (e.g. "LIMIT_NOFILE") followed by an equal
sign, followed by a numeric limit. Optionally, separated by colon a second numeric limit may be
specified. If two are specified this refers to the soft and hard limits, respectively. If only one
limit is specified the setting sets both limits in one.
--tasks-max=TASKS¶Takes a non-zero unsigned integer as argument. Configures the maximum number of tasks
(i.e. threads, where each process is at least one thread) the user may have at any given time. This
limit applies to all tasks forked off the user's sessions, even if they change user identity via
su(1)
or a similar tool. Use --rlimit=LIMIT_NPROC= to place a limit on the tasks actually
running under the UID of the user, thus excluding any child processes that might have changed user
identity. This controls the TasksMax= setting of the per-user systemd slice unit
user-$UID.slice. See
systemd.resource-control(5)
for further details.
--memory-high=BYTES, --memory-max=BYTES¶Set a limit on the memory a user may take up on a system at any given time in bytes
(the usual K, M, G, … suffixes are supported, to the base of 1024). This includes all memory used by
the user itself and all processes they forked off that changed user credentials. This controls the
MemoryHigh= and MemoryMax= settings of the per-user systemd
slice unit user-$UID.slice. See
systemd.resource-control(5)
for further details.
--cpu-weight=WEIGHT, --io-weight=WEIGHT¶Set CPU and IO scheduling weights of the processes of the user, including those of
processes forked off by the user that changed user credentials. Takes a numeric value in the range
1…10000. This controls the CPUWeight= and IOWeight= settings of
the per-user systemd slice unit user-$UID.slice. See
systemd.resource-control(5)
for further details.
--storage=STORAGE¶Selects the storage mechanism to use for this home directory. Takes one of
"luks", "fscrypt", "directory",
"subvolume", "cifs". For details about these mechanisms, see
above. If a new home directory is created and the storage type is not specifically specified,
homed.conf(5)
defines which default storage to use.
--image-path=PATH¶Takes a file system path. Configures where to place the user's home directory. When
LUKS2 storage is used refers to the path to the loopback file, otherwise to the path to the home
directory (which may be in /home/ or any other accessible filesystem). When
unspecified defaults to /home/$USER.home when LUKS storage is used and
/home/$USER.homedir for the other storage mechanisms. Not defined for the
"cifs" storage mechanism. To use LUKS2 storage on a regular block device (for
example a USB stick) pass the path to the block device here. Specifying the path to a directory here
when using LUKS2 storage is not allowed. Similar, specifying the path to a regular file or device
node is not allowed if any of the other storage backends are used.
--drop-caches=BOOL¶Automatically flush OS file system caches on logout. This is useful in combination with the fscrypt storage backend to ensure the OS does not keep decrypted versions of the files and directories in memory (and accessible) after logout. This option is also supported on other backends, but should not bring any benefit there. Defaults to off, except if the selected storage backend is fscrypt, where it defaults to on. Note that flushing OS caches will negatively influence performance of the OS shortly after logout.
--fs-type=TYPE¶When LUKS2 storage is used configures the file system type to use inside the home
directory LUKS2 container. One of "btrfs", "ext4",
"xfs". If not specified
homed.conf(5)
defines which default file system type to use. Note that "xfs" is not recommended as
its support for file system resizing is too limited.
--luks-discard=BOOL¶When LUKS2 storage is used configures whether to enable the
"discard" feature of the file system. If enabled the file system on top of the LUKS2
volume will report empty block information to LUKS2 and the loopback file below, ensuring that empty
space in the home directory is returned to the backing file system below the LUKS2 volume, resulting
in a "sparse" loopback file. This option mostly defaults to off, since this permits over-committing
home directories which results in I/O errors if the underlying file system runs full while the upper
file system wants to allocate a block. Such I/O errors are generally not handled well by file systems
nor applications. When LUKS2 storage is used on top of regular block devices (instead of on top a
loopback file) the discard logic defaults to on.
--luks-offline-discard=BOOL¶Similar to --luks-discard=, controls the trimming of the file
system. However, while --luks-discard= controls what happens when the home directory
is active, --luks-offline-discard= controls what happens when it becomes inactive,
i.e. whether to trim/allocate the storage when deactivating the home directory. This option defaults
to on, to ensure disk space is minimized while a user is not logged in.
--luks-extra-mount-options=OPTIONS¶Takes a string containing additional mount options to use when mounting the LUKS volume. If specified, this string will be appended to the default, built-in mount options.
--luks-cipher=CIPHER, --luks-cipher-mode=MODE, --luks-volume-key-size=BYTES, --luks-pbkdf-type=TYPE, --luks-pbkdf-hash-algorithm=ALGORITHM, --luks-pbkdf-force-iterations=ITERATIONS, --luks-pbkdf-time-cost=SECONDS, --luks-pbkdf-memory-cost=BYTES, --luks-pbkdf-parallel-threads=THREADS, --luks-sector-size=BYTES¶Configures various cryptographic parameters for the LUKS2 storage mechanism. See cryptsetup(8) for details on the specific attributes.
Note that homectl uses bytes for key size, like
/proc/crypto, but cryptsetup(8)
uses bits.
--auto-resize-mode=¶Configures whether to automatically grow and/or shrink the backing file system on
login and logout. Takes one of the strings "off", "grow",
"shrink-and-grow". Only applies to the LUKS2 backend currently, and if the btrfs
file system is used inside it (since only then online growing/shrinking of the file system is
supported). Defaults to "shrink-and-grow", if LUKS2/btrfs is used, otherwise is
off. If set to "off" no automatic shrinking/growing during login or logout is
done. If set to "grow" the home area is grown to the size configured via
--disk-size= should it currently be smaller. If it already matches the configured
size or is larger no operation is executed. If set to "shrink-and-grow" the home
area is also resized during logout to the minimal size the used disk space and file system
constraints permit. This mode thus ensures that while a home area is activated it is sized to the
configured size, but while deactivated it is compacted taking up only the minimal space possible.
Note that if the system is powered off abnormally or if the user otherwise not logged out cleanly the
shrinking operation will not take place, and the user has to re-login/logout again before it is
executed again.
--rebalance-weight=¶Configures the weight parameter for the free disk space rebalancing logic. Only
applies to the LUKS2 backend (since for the LUKS2 backend disk space is allocated from a per-user
loopback file system instead of immediately from a common pool like the other backends do it). In
regular intervals free disk space in the active home areas and their backing storage is redistributed
among them, taking the weight value configured here into account. Expects an integer in the range
1…10000, or the special string "off". If not specified defaults to 100. The weight
is used to scale free space made available to the home areas: a home area with a weight of 200 will
get twice the free space as one with a weight of 100; a home area with a weight of 50 will get half
of that. The backing file system will be assigned space for a weight of 20. If set to
"off" no automatic free space distribution is done for this home area. Note that
resizing the home area explicitly (with homectl resize see below) will implicitly
turn off the automatic rebalancing. To reenable the automatic rebalancing use
--rebalance-weight= with an empty parameter.
--nosuid=BOOL, --nodev=BOOL, --noexec=BOOL¶Configures the "nosuid", "nodev" and
"noexec" mount options for the home directories. By default "nodev"
and "nosuid" are on, while "noexec" is off. For details about these
mount options see mount(8).
--cifs-domain=DOMAIN, --cifs-user-name=USER, --cifs-service=SERVICE, --cifs-extra-mount-options=OPTIONS¶Configures the Windows File Sharing (CIFS) domain and user to associate with the home
directory/user account, as well as the file share ("service") to mount as directory. The latter is
used when "cifs" storage is selected. The file share should be specified in format
"//". The
directory part is optional — if not specified the home directory will be placed in the top-level
directory of the share. The host/share/directory/…--cifs-extra-mount-options= setting allows specifying
additional mount options when mounting the share, see mount.cifs(8)
for details.
--stop-delay=SECS¶Configures the time the per-user service manager shall continue to run after the all sessions of the user ended. The default is configured in logind.conf(5) (for home directories of LUKS2 storage located on removable media this defaults to 0 though). A longer time makes sure quick, repetitive logins are more efficient as the user's service manager doesn't have to be started every time.
--kill-processes=BOOL¶Configures whether to kill all processes of the user on logout. The default is configured in logind.conf(5).
--auto-login=BOOL¶Takes a boolean argument. Configures whether the graphical UI of the system should automatically log this user in if possible. Defaults to off. If less or more than one user is marked this way automatic login is disabled.
--session-launcher=LAUNCHER¶Takes a string argument. Configures the user's preferred session launcher
.desktop entry file (i.e. "gnome", "plasma", or other names that
appear in /usr/share/xesssions/ or /usr/share/wayland-sessions).
This is read by the display manager to pick the default session that is launched when the user logs in.
--session-type=TYPE¶Takes a string argument. Configures the user's preferred session type
(i.e. "x11", "wayland", and other values accepted by
$XDG_SESSION_TYPE). This is read by the display manage to pick the
default session type the user is logged into.
The following commands are understood:
List all home directories (along with brief details) currently managed by
systemd-homed.service. This command is also executed if none is specified on the
command line. (Note that the list of users shown by this command does not include users managed by
other subsystems, such as system users or any traditional users listed in
/etc/passwd.)
USER [USER…]¶Activate one or more home directories. The home directories of each listed user will
be activated and made available under their mount points (typically in
/home/$USER). Note that any home activated this way stays active indefinitely,
until it is explicitly deactivated again (with deactivate, see below), or the user
logs in and out again and it thus is deactivated due to the automatic deactivation-on-logout
logic.
Activation of a home directory involves various operations that depend on the selected storage mechanism. If the LUKS2 mechanism is used, this generally involves: inquiring the user for a password, setting up a loopback device, validating and activating the LUKS2 volume, checking the file system, mounting the file system, and potentially changing the ownership of all included files to the correct UID/GID.
USER [USER…]¶Deactivate one or more home directories. This undoes the effect of activate.
USER [USER…]¶Show various details about the specified home directories. This shows various
information about the home directory and its user account, including runtime data such as current
state, disk use and similar. Combine with --json= to show the detailed JSON user
record instead, possibly combined with --export-format= to suppress certain aspects
of the output.
USER [USER…]¶Validate authentication credentials of a home directory. This queries the caller for a password (or similar) and checks that it correctly unlocks the home directory. This leaves the home directory in the state it is in, i.e. it leaves the home directory in inactive state if it was inactive before, and in active state if it was active before.
USER, create --identity=PATH [USER]¶Create a new home directory/user account of the specified name. Use the various user record property options (as documented above) to control various aspects of the home directory and its user accounts.
The specified user name should follow the strict syntax described on User/Group Name Syntax.
USER¶Remove a home directory/user account. This will remove both the home directory's user record and the home directory itself, and thus delete all files and directories owned by the user.
USER, update --identity=PATH [USER]¶Update a home directory/user account. Use the various user record property options
(as documented above) to make changes to the account, or alternatively provide a full, updated JSON
user record via the --identity= option.
Note that changes to user records not signed by a cryptographic private key available locally
are not permitted, unless --identity= is used with a user record that is already
correctly signed by a recognized private key.
USER¶Change the password of the specified home directory/user account.
USER BYTES¶Change the disk space assigned to the specified home directory. If the LUKS2 storage
mechanism is used this will automatically resize the loopback file and the file system contained
within. Note that if "ext4" is used inside of the LUKS2 volume, it is necessary to
deactivate the home directory before shrinking it (i.e the user has to log out). Growing can be done
while the home directory is active. If "xfs" is used inside of the LUKS2 volume the
home directory may not be shrunk whatsoever. On all three of "ext4",
"xfs" and "btrfs" the home directory may be grown while the user is
logged in, and on the latter also shrunk while the user is logged in. If the
"subvolume", "directory", "fscrypt" storage
mechanisms are used, resizing will change file system quota. The size parameter may make use of the
usual suffixes B, K, M, G, T (to the base of 1024). The special strings "min" and
"max" may be specified in place of a numeric size value, for minimizing or
maximizing disk space assigned to the home area, taking constraints of the file system, disk usage inside
the home area and on the backing storage into account.
USER¶Temporarily suspend access to the user's home directory and remove any associated cryptographic keys from memory. Any attempts to access the user's home directory will stall until the home directory is unlocked again (i.e. re-authenticated). This functionality is primarily intended to be used during system suspend to make sure the user's data cannot be accessed until the user re-authenticates on resume. This operation is only defined for home directories that use the LUKS2 storage mechanism.
USER¶Resume access to the user's home directory again, undoing the effect of lock above. This requires authentication of the user, as the cryptographic keys required for access to the home directory need to be reacquired.
Execute the lock command on all suitable home directories at once. This operation is generally executed on system suspend (i.e. by systemctl suspend and related commands), to ensure all active user's cryptographic keys for accessing their home directories are removed from memory.
Execute the deactivate command on all active home directories at
once. This operation is generally executed on system shut down (i.e. by systemctl
poweroff and related commands), to ensure all active user's home directories are fully
deactivated before /home/ and related file systems are unmounted.
USER COMMAND…¶Activate the specified user's home directory, run the specified command (under the caller's identity, not the specified user's) and deactivate the home directory afterwards again (unless the user is logged in otherwise). This command is useful for running privileged backup scripts and such, but requires authentication with the user's credentials in order to be able to unlock the user's home directory.
Rebalance free disk space between active home areas and the backing storage. See
--rebalance-weight= above. This executes no operation unless there's at least one
active LUKS2 home area that has disk space rebalancing enabled. This operation is synchronous: it
will only complete once disk space is rebalanced according to the rebalancing weights. Note that
rebalancing also takes place automatically in the background in regular intervals. Use this command
to synchronously ensure disk space is properly redistributed before initiating an operation requiring
large amounts of disk space.
This command is supposed to be invoked during the initial boot of the system. It
checks whether any regular home area exists so far, and if not queries the user interactively on the
console for user name and password and creates one. Alternatively, if one or more service credentials
whose name starts with "home.create." are passed to the command (containing a user
record in JSON format) these users are automatically created at boot.
This command is invoked by the systemd-homed-firstboot.service service
unit.
When invoked with the firstboot command, homectl supports the
service credentials logic as implemented by
ImportCredential=/LoadCredential=/SetCredential=
(see systemd.exec(5) for
details). The following credentials are used when passed in:
home.create.*¶If one or more credentials whose names begin with "home.create.",
followed by a valid UNIX username are passed, a new home area is created, one for each specified user
record.
systemd.firstboot=¶This boolean will disable the effect of homectl firstboot command. It's primarily interpreted by systemd-firstboot(1).
On success, 0 is returned, a non-zero failure code otherwise.
When a command is invoked with with, the exit status of the child is propagated. Effectively, homectl will exit without error if the command is successfully invoked and finishes successfully.
$SYSTEMD_LOG_LEVEL¶The maximum log level of emitted messages (messages with a higher
log level, i.e. less important ones, will be suppressed). Takes a comma-separated list of values. A
value may be 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. Each value may optionally be prefixed with one of console,
syslog, kmsg or journal followed by a
colon to set the maximum log level for that specific log target (e.g.
SYSTEMD_LOG_LEVEL=debug,console:info specifies to log at debug level except when
logging to the console which should be at info level). Note that the global maximum log level takes
priority over any per target maximum log levels.
$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_LOG_RATELIMIT_KMSG¶ Whether to ratelimit kmsg or not. Takes a boolean.
Defaults to "true". If disabled, systemd will not ratelimit messages written to kmsg.
$SYSTEMD_PAGER, $PAGER¶Pager to use when --no-pager is not given.
$SYSTEMD_PAGER is used if set; otherwise $PAGER is used.
If neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known
pager implementations is tried in turn, including
less(1)
and
more(1),
until one is found. If no pager implementation is discovered, no pager is invoked. Setting those
environment variables to an empty string or the value "cat" is equivalent to passing
--no-pager.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER
and $PAGER can only be used to disable the pager (with "cat" or
""), and are otherwise 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.
Note that setting the regular $LESS environment variable has no effect
for less invocations by systemd tools.
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).
Note that setting the regular $LESSCHARSET environment variable has no effect
for less invocations by systemd tools.
$SYSTEMD_PAGERSECURE¶Common pager commands like less(1), in
addition to "paging", i.e. scrolling through the output, support opening of or writing to other files
and running arbitrary shell commands. When commands are invoked with elevated privileges, for example
under sudo(8) or
pkexec(1), the
pager becomes a security boundary. Care must be taken that only programs with strictly limited
functionality are used as pagers, and unintended interactive features like opening or creation of new
files or starting of subprocesses are not allowed. "Secure mode" for the pager may be enabled as
described below, if the pager supports that (most pagers are not written in a way
that takes this into consideration). It is recommended to either explicitly enable "secure mode" or to
completely disable the pager using --no-pager or PAGER=cat when
allowing untrusted users to execute commands with elevated privileges.
This option takes a boolean argument. When set to true, the "secure mode" of the pager is
enabled. In "secure mode", LESSSECURE=1 will be set when invoking the pager, which
instructs the pager to disable commands that open or create new files or start new subprocesses.
Currently only less(1) is known
to understand this variable and implement "secure mode".
When set to false, no limitation is placed on the pager. Setting
SYSTEMD_PAGERSECURE=0 or not removing it from the inherited environment may allow
the user to invoke arbitrary commands.
When $SYSTEMD_PAGERSECURE is not set, systemd tools attempt to automatically
figure out if "secure mode" should be enabled and whether the pager supports it. "Secure mode" is
enabled if the effective UID is not the same as the owner of the login session, see
geteuid(2)
and
sd_pid_get_owner_uid(3),
or when running under
sudo(8) or similar
tools ($SUDO_UID is set [1]). In those cases,
SYSTEMD_PAGERSECURE=1 will be set and pagers which are not known to implement
"secure mode" will not be used at all. Note that this autodetection only covers the most common
mechanisms to elevate privileges and is intended as convenience. It is recommended to explicitly set
$SYSTEMD_PAGERSECURE or disable the pager.
Note that if the $SYSTEMD_PAGER or $PAGER variables are to
be honoured, other than to disable the pager, $SYSTEMD_PAGERSECURE must be set
too.
$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.
Example 1. Create a user "waldo" in the administrator group "wheel", and
assign 500 MiB disk space to them.
homectl create waldo --real-name="Waldo McWaldo" -G wheel --disk-size=500M
Example 2. Create a user "wally" on a USB stick, and assign a maximum of 500 concurrent
tasks to them.
homectl create wally --real-name="Wally McWally" --image-path=/dev/disk/by-id/usb-SanDisk_Ultra_Fit_476fff954b2b5c44-0:0 --tasks-max=500
Example 3. Change nice level of user "odlaw" to +5 and make sure the environment variable
$SOME is set to the string "THING" for them on login.
homectl update odlaw --nice=5 --setenv=SOME=THING
Example 4. Set up authentication with a YubiKey security token using PKCS#11/PIV:
# Clear the Yubikey from any old keys (careful!) ykman piv reset # Generate a new private/public key pair on the device, store the public key in 'pubkey.pem'. ykman piv generate-key -a RSA2048 9d pubkey.pem # Create a self-signed certificate from this public key, and store it on the device. ykman piv generate-certificate --subject "Knobelei" 9d pubkey.pem # We don't need the public key on disk anymore rm pubkey.pem # Allow the security token to unlock the account of user 'lafcadio'. homectl update lafcadio --pkcs11-token-uri=auto
Example 5. Set up authentication with a FIDO2 security token:
# Allow a FIDO2 security token to unlock the account of user 'nihilbaxter'. homectl update nihilbaxter --fido2-device=auto
systemd(1), systemd-homed.service(8), homed.conf(5), userdbctl(1), useradd(8), cryptsetup(8)
[1] It is recommended for other tools to set and check $SUDO_UID as appropriate,
treating it is a common interface.