Provided by: systemd-homed_256.5-2ubuntu3.1_amd64 
NAME
homectl, systemd-homed-firstboot.service - Create, remove, change or inspect home directories
SYNOPSIS
homectl [OPTIONS...] {COMMAND} [NAME...]
DESCRIPTION
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.
OPTIONS
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[1]. 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).
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 256.
-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
Print a short help text and exit.
--version
Print a short version string and exit.
USER RECORD PROPERTIES
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.
Added in version 245.
--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.
Added in version 245.
--email-address=EMAIL
Takes an electronic mail address to associate with the user. On log-in the $EMAIL environment
variable is initialized from this value.
Added in version 245.
--location=TEXT
Takes location specification for this user. This is free-form text, which might or might not be
usable by geo-location applications. Example: --location="Berlin, Germany" or --location="Basement,
Room 3a"
Added in version 245.
--icon-name=ICON
Takes an icon name to associate with the user, following the scheme defined by the Icon Naming
Specification[2].
Added in version 245.
--home-dir=PATH, -dPATH
Takes a path to use as home directory for the user. Note that this is the directory the user's home
directory is mounted to while the user is logged in. This is not where the user's data is actually
stored, see --image-path= for that. If not specified defaults to /home/$USER.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 254.
--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/.
Added in version 245.
--shell=SHELL
Takes a file system path. Specifies the shell binary to execute on terminal logins. If not specified
defaults to /bin/bash.
Added in version 245.
--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=.
Added in version 245.
--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).)
Added in version 245.
--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 suitible 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.
Added in version 245.
--ssh-authorized-keys=KEYS
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.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 251.
--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.
Added in version 246.
--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.)
Added in version 249.
--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.)
Added in version 249.
--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.)
Added in version 249.
--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.
Added in version 247.
--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[3] for more information about blob
directories.
Added in version 256.
--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=FILENAME=PATH for the known filenames defined in
User Record Blob Directories[3].
Added in version 256.
--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).
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 245.
--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".
Added in version 245.
--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.
Added in version 245.
--password-change-now=BOOL
Takes a boolean argument. If true the user is asked to change their password on next login.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 245.
--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
Added in version 245.
--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.
Added in version 245.
--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).
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 245.
--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-$UID.slice. See systemd.resource-
control(5) for further details.
Added in version 245.
--cpu-weight=WEIGHT, --io-weight=WEIGHT
Set CPU and IO scheduling weights of the processes of the user, including those of processes forked
off by the user that changed user credentials. Takes a numeric value in the range 1...10000. This
controls the CPUWeight= and IOWeight= settings of the per-user systemd slice unit user-$UID.slice.
See systemd.resource-control(5) for further details.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 250.
--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.
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 246.
--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.
Added in version 250.
--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.
Added in version 245.
--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.
Added in version 250.
--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.
Added in version 250.
--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).
Added in version 245.
--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 "//host/share/directory/...". The
directory part is optional — if not specified the home directory will be placed in the top-level
directory of the share. The --cifs-extra-mount-options= setting allows specifying additional mount
options when mounting the share, see mount.cifs(8) for details.
Added in version 245.
--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.
Added in version 245.
--kill-processes=BOOL
Configures whether to kill all processes of the user on logout. The default is configured in
logind.conf(5).
Added in version 245.
--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.
Added in version 245.
--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.
Added in version 256.
--session-type=TYPE
Takes a string argument. Configures the user's preferred session type (i.e. "x11", "wayland", and
other values accepted by $XDG_SESSION_TYPE). This is read by the display manage to pick the default
session type the user is logged into.
Added in version 256.
COMMANDS
The following commands are understood:
list
List all home directories (along with brief details) currently managed by systemd-homed.service. This
command is also executed if none is specified on the command line. (Note that the list of users shown
by this command does not include users managed by other subsystems, such as system users or any
traditional users listed in /etc/passwd.)
Added in version 245.
activate USER [USER...]
Activate one or more home directories. The home directories of each listed user will be activated and
made available under their mount points (typically in /home/$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.
Added in version 245.
deactivate USER [USER...]
Deactivate one or more home directories. This undoes the effect of activate.
Added in version 245.
inspect 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.
Added in version 245.
authenticate 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.
Added in version 245.
create 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[4].
Added in version 245.
remove 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.
Added in version 245.
update 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.
Added in version 245.
passwd USER
Change the password of the specified home directory/user account.
Added in version 245.
resize 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.
Added in version 245.
lock 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.
Added in version 245.
unlock 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.
Added in version 245.
lock-all
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.
Added in version 245.
deactivate-all
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.
Added in version 247.
with 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.
Added in version 245.
rebalance
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.
Added in version 250.
firstboot
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.
Added in version 256.
CREDENTIALS
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.
Added in version 256.
KERNEL COMMAND LINE
systemd.firstboot=
This boolean will disable the effect of homectl firstboot command. It's primarily interpreted by
systemd-firstboot(1).
Added in version 256.
EXIT STATUS
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.
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). 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 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.
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
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 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
SEE ALSO
systemd(1), systemd-homed.service(8), homed.conf(5), userdbctl(1), useradd(8), cryptsetup(8)
NOTES
1. JSON User Records
https://systemd.io/USER_RECORD
2. Icon Naming Specification
https://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
3. User Record Blob Directories
https://systemd.io/USER_RECORD_BLOB_DIRS
4. User/Group Name Syntax
https://systemd.io/USER_NAMES