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
--real-name=NAME, -c NAME
The real name for the user. This corresponds with the
GECOS field on classic UNIX NSS records.
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.
Takes an electronic mail address to associate with the
user. On log-in the $EMAIL environment variable is initialized from
Takes location specification for this user. This is
free-form text, which might or might not be usable by geo-location
applications. Example: --location="Berlin, Germany" or
--location="Basement, Room 3a"
Takes an icon name to associate with the user, following
the scheme defined by the Icon Naming Specification.
Takes a path to use as home directory for the user. Note
that this is the directory the user's home directory is mounted to while the
user is logged in. This is not where the user's data is actually stored, see
--image-path= for that. If not specified defaults to /home/$USER.
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
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 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
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.
These options take a space separated list of process
capabilities (e.g. CAP_WAKE_ALARM
, ...) 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
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/.
Takes a file system path. Specifies the shell binary to
execute on terminal logins. If not specified defaults to /bin/bash.
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=.
Takes a time zone location name that sets the timezone
for the specified user. When the user logs in the $TZ
variable is initialized from this setting. Example:
will result in the environment variable
"TZ=:Europe/Amsterdam". (":" is used intentionally as part
of the timezone specification, see tzset(3)
Takes a specifier indicating the preferred language of
the user. The $LANG environment variable is initialized from this value
on login, and thus a value suitable for this environment variable is accepted
here, for example --language=de_DE.UTF8.
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.
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.
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 not support some algorithms.
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
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
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.
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
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.)
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.)
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
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
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.
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
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".
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
Takes a boolean argument. If true the user is asked to
change their password on next login.
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,
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
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.
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
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.
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.
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
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.
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
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
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
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
setting of the per-user systemd slice unit user-$UID.slice.
for further details.
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
settings of the per-user systemd
slice unit user-$UID.slice. See systemd.resource-control(5)
Set CPU and IO scheduling weights of the processes of the
user, including those of processes forked off by the user that changed user
credentials. Takes a numeric value in the range 1...10000. This controls the
settings of the per-user systemd slice
unit user-$UID.slice. See systemd.resource-control(5)
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)
default storage to use.
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.
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
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
defines which default file system type to use. Note that
"xfs" is not recommended as its support for file system resizing is
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
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.
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.
Configures various cryptographic parameters for the LUKS2
storage mechanism. See cryptsetup(8)
for details on the specific
Note that homectl uses bytes for key size, like
/proc/crypto, but cryptsetup(8) uses bits.
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
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.
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)
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
directory part is optional — if not specified the home directory will
be placed in the top-level directory of the share. The
setting allows specifying additional mount
options when mounting the share, see mount.cifs(8)
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.
Configures whether to kill all processes of the user on
logout. The default is configured in logind.conf(5)
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.
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.)
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
, 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.
deactivate USER [USER...]
Deactivate one or more home directories. This undoes the
effect of activate.
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.
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.
create USER, create
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.
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.
update USER, update
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
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
Change the password of the specified home directory/user
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.
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.
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
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
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.
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.
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.