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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:35:18 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:35:18 +0000
commitb750101eb236130cf056c675997decbac904cc49 (patch)
treea5df1a06754bdd014cb975c051c83b01c9a97532 /man/homectl.xml
parentInitial commit. (diff)
downloadsystemd-b750101eb236130cf056c675997decbac904cc49.tar.xz
systemd-b750101eb236130cf056c675997decbac904cc49.zip
Adding upstream version 252.22.upstream/252.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+<?xml version='1.0'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
+
+<refentry id="homectl" conditional='ENABLE_HOMED'
+ xmlns:xi="http://www.w3.org/2001/XInclude">
+
+ <refentryinfo>
+ <title>homectl</title>
+ <productname>systemd</productname>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>homectl</refentrytitle>
+ <manvolnum>1</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>homectl</refname>
+ <refpurpose>Create, remove, change or inspect home directories</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <cmdsynopsis>
+ <command>homectl</command>
+ <arg choice="opt" rep="repeat">OPTIONS</arg>
+ <arg choice="req">COMMAND</arg>
+ <arg choice="opt" rep="repeat">NAME</arg>
+ </cmdsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><command>homectl</command> may be used to create, remove, change or inspect a user's home
+ directory. It's primarily a command interfacing with
+ <citerefentry><refentrytitle>systemd-homed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ which manages home directories of users.</para>
+
+ <para>Home directories managed by <filename>systemd-homed.service</filename> 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 <filename>systemd-homed.service</filename> also implies existence and encapsulation of a home
+ directory. The user account and home directory become the same concept.</para>
+
+ <para>The following backing storage mechanisms are supported:</para>
+
+ <itemizedlist>
+ <listitem><para>An individual LUKS2 encrypted loopback file for a user, stored in
+ <filename>/home/*.home</filename>. 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.</para></listitem>
+
+ <listitem><para>Similar, but the LUKS2 encrypted file system is located on regular block device, such
+ as an 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.</para></listitem>
+
+ <listitem><para>An encrypted directory using <literal>fscrypt</literal> on file systems that support it
+ (at the moment this is primarily <literal>ext4</literal>), located in
+ <filename>/home/*.homedir</filename>. 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.</para></listitem>
+
+ <listitem><para>A <literal>btrfs</literal> subvolume for each user, also located in
+ <filename>/home/*.homedir</filename>. This provides no encryption, but good quota
+ support.</para></listitem>
+
+ <listitem><para>A regular directory for each user, also located in
+ <filename>/home/*.homedir</filename>. This provides no encryption, but is a suitable fallback
+ available on all machines, even where LUKS2, <literal>fscrypt</literal> or <literal>btrfs</literal>
+ support is not available.</para></listitem>
+
+ <listitem><para>An individual Windows file share (CIFS) for each user.</para></listitem>
+ </itemizedlist>
+
+ <para>Note that <filename>systemd-homed.service</filename> and <command>homectl</command> will not manage
+ "classic" UNIX user accounts as created with <citerefentry
+ project='man-pages'><refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum></citerefentry> 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.</para>
+
+ <para>Note that users/home directories managed via <command>systemd-homed.service</command> do not show
+ up in <filename>/etc/passwd</filename> and similar files, they are synthesized via glibc NSS during
+ runtime. They are thus resolvable and may be enumerated via the <citerefentry
+ project='man-pages'><refentrytitle>getent</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ tool.</para>
+
+ <para>This tool interfaces directly with <filename>systemd-homed.service</filename>, 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
+ <citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
+
+ <para>Home directories managed by <filename>systemd-homed.service</filename> are usually in one of two
+ states, or in a transition state between them: when <literal>active</literal> they are unlocked and
+ mounted, and thus accessible to the system and its programs; when <literal>inactive</literal> 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.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Options</title>
+
+ <para>The following general options are understood (further options that control the various properties
+ of user records managed by <filename>systemd-homed.service</filename> are documented further
+ down):</para>
+
+ <variablelist>
+
+ <varlistentry>
+ <term><option>--identity=</option><replaceable>FILE</replaceable></term>
+
+ <listitem><para>Read the user's JSON record from the specified file. If passed as
+ <literal>-</literal> read the user record from standard input. The supplied JSON object must follow
+ the structure documented in <ulink url="https://systemd.io/USER_RECORD">JSON User Records</ulink>.
+ This option may be used in conjunction with the <command>create</command> and
+ <command>update</command> commands (see below), where it allows configuring the user record in JSON
+ as-is, instead of setting the individual user record properties (see below).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--json=</option><replaceable>FORMAT</replaceable></term>
+ <term><option>-j</option></term>
+
+ <listitem><para>Controls whether to output the user record in JSON format, if the
+ <command>inspect</command> command (see below) is used. Takes one of <literal>pretty</literal>,
+ <literal>short</literal> or <literal>off</literal>. If <literal>pretty</literal> human-friendly
+ whitespace and newlines are inserted in the output to make the JSON data more readable. If
+ <literal>short</literal> all superfluous whitespace is suppressed. If <literal>off</literal> (the
+ default) the user information is not shown in JSON format but in a friendly human readable formatting
+ instead. The <option>-j</option> option picks <literal>pretty</literal> when run interactively and
+ <literal>short</literal> otherwise.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--export-format=</option><replaceable>FORMAT</replaceable></term>
+ <term><option>-E</option></term>
+ <term><option>-EE</option></term>
+
+ <listitem><para>When used with the <command>inspect</command> verb in JSON mode (see above) may be
+ used to suppress certain aspects of the JSON user record on output. Specifically, if
+ <literal>stripped</literal> format is used the binding and runtime fields of the record are
+ removed. If <literal>minimal</literal> format is used the cryptographic signature is removed too. If
+ <literal>full</literal> 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: <command>homectl inspect -EE | ssh
+ root@othersystem homectl create -i-</command> may be used as simple command line for replicating a
+ user on another host. <option>-E</option> is equivalent to <option>-j --export-format=stripped</option>,
+ <option>-EE</option> to <option>-j --export-format=minimal</option>. Note that when replicating user
+ accounts user records acquired in <literal>stripped</literal> 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 <literal>minimal</literal> 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.</para></listitem>
+ </varlistentry>
+
+ <xi:include href="user-system-options.xml" xpointer="host" />
+ <xi:include href="user-system-options.xml" xpointer="machine" />
+
+ <xi:include href="standard-options.xml" xpointer="no-pager" />
+ <xi:include href="standard-options.xml" xpointer="no-legend" />
+ <xi:include href="standard-options.xml" xpointer="no-ask-password" />
+ <xi:include href="standard-options.xml" xpointer="help" />
+ <xi:include href="standard-options.xml" xpointer="version" />
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>User Record Properties</title>
+
+ <para>The following options control various properties of the user records/home directories that
+ <filename>systemd-homed.service</filename> manages. These switches may be used in conjunction with the
+ <command>create</command> and <command>update</command> commands for configuring various aspects of the
+ home directory and the user account:</para>
+
+ <variablelist>
+
+ <varlistentry>
+ <term><option>--real-name=</option><replaceable>NAME</replaceable></term>
+ <term><option>-c</option> <replaceable>NAME</replaceable></term>
+
+ <listitem><para>The real name for the user. This corresponds with the GECOS field on classic UNIX NSS
+ records.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--realm=</option><replaceable>REALM</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--email-address=</option><replaceable>EMAIL</replaceable></term>
+
+ <listitem><para>Takes an electronic mail address to associate with the user. On log-in the
+ <varname>$EMAIL</varname> environment variable is initialized from this value.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--location=</option><replaceable>TEXT</replaceable></term>
+
+ <listitem><para>Takes location specification for this user. This is free-form text, which might or
+ might not be usable by geo-location applications. Example: <option>--location="Berlin,
+ Germany"</option> or <option>--location="Basement, Room 3a"</option></para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--icon-name=</option><replaceable>ICON</replaceable></term>
+
+ <listitem><para>Takes an icon name to associate with the user, following the scheme defined by the <ulink
+ url="https://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">Icon Naming
+ Specification</ulink>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--home-dir=</option><replaceable>PATH</replaceable></term>
+ <term><option>-d</option><replaceable>PATH</replaceable></term>
+
+ <listitem><para>Takes a path to use as home directory for the user. Note that this is the directory
+ the user's home directory is mounted to while the user is logged in. This is not where the user's
+ data is actually stored, see <option>--image-path=</option> for that. If not specified defaults to
+ <filename>/home/$USER</filename>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--uid=</option><replaceable>UID</replaceable></term>
+
+ <listitem><para>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
+ <command>systemd-homed</command> 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.</para>
+
+ <para>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 <emphasis>binding</emphasis>), 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.</para>
+
+ <para>Note that users managed by <command>systemd-homed</command> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--member-of=</option><replaceable>GROUP</replaceable></term>
+ <term><option>-G</option> <replaceable>GROUP</replaceable></term>
+
+ <listitem><para>Takes a comma-separated list of auxiliary UNIX groups this user shall belong
+ to. Example: <option>--member-of=wheel</option> to provide the user with administrator
+ privileges. Note that <command>systemd-homed</command> 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 <citerefentry
+ project='man-pages'><refentrytitle>groupadd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+ 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--skel=</option><replaceable>PATH</replaceable></term>
+
+ <listitem><para>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 <filename>/etc/skel/</filename>.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--shell=</option><replaceable>SHELL</replaceable></term>
+
+ <listitem><para>Takes a file system path. Specifies the shell binary to execute on terminal
+ logins. If not specified defaults to <filename>/bin/bash</filename>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--setenv=</option><replaceable>VARIABLE</replaceable>[=<replaceable>VALUE</replaceable>]</term>
+
+ <listitem><para>Takes an environment variable assignment to set for all user processes. May be used
+ multiple times to set multiple environment variables. When <literal>=</literal> and
+ <replaceable>VALUE</replaceable> are omitted, the value of the variable with the same name in the
+ program environment will be used.</para>
+
+ <para>Note that a number of other settings also result in environment variables to be set for the
+ user, including <option>--email=</option>, <option>--timezone=</option> and
+ <option>--language=</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--timezone=</option><replaceable>TIMEZONE</replaceable></term>
+
+ <listitem><para>Takes a time zone location name that sets the timezone for the specified user. When
+ the user logs in the <varname>$TZ</varname> environment variable is initialized from this
+ setting. Example: <option>--timezone=Europe/Amsterdam</option> will result in the environment
+ variable <literal>TZ=:Europe/Amsterdam</literal>. (<literal>:</literal> is used intentionally as part
+ of the timezone specification, see
+ <citerefentry project='man-pages'><refentrytitle>tzset</refentrytitle><manvolnum>3</manvolnum></citerefentry>.)
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--language=</option><replaceable>LANG</replaceable></term>
+
+ <listitem><para>Takes a specifier indicating the preferred language of the user. The
+ <varname>$LANG</varname> environment variable is initialized from this value on login, and thus a
+ value suitable for this environment variable is accepted here, for example
+ <option>--language=de_DE.UTF8</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--ssh-authorized-keys=</option><replaceable>KEYS</replaceable></term>
+ <listitem><para>Either takes a SSH authorized key line to associate with the user record or a
+ <literal>@</literal> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--pkcs11-token-uri=</option><replaceable>URI</replaceable></term>
+ <listitem><para>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.</para>
+
+ <para>Instead of a valid PKCS#11 URI, the special strings <literal>list</literal> and
+ <literal>auto</literal> may be specified. If <literal>list</literal> is passed, a brief table of
+ suitable, currently plugged in PKCS#11 hardware tokens is shown, along with their URIs. If
+ <literal>auto</literal> 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.</para>
+
+ <para>Note that many hardware security tokens implement both PKCS#11/PIV and FIDO2 with the
+ <literal>hmac-secret</literal> extension (for example: the YubiKey 5 series), as supported with the
+ <option>--fido2-device=</option> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--fido2-credential-algorithm=</option><replaceable>STRING</replaceable></term>
+ <listitem><para>Specify COSE algorithm used in credential generation. The default value is
+ <literal>es256</literal>. Supported values are <literal>es256</literal>, <literal>rs256</literal>
+ and <literal>eddsa</literal>.</para>
+
+ <para><literal>es256</literal> denotes ECDSA over NIST P-256 with SHA-256. <literal>rs256</literal>
+ denotes 2048-bit RSA with PKCS#1.5 padding and SHA-256. <literal>eddsa</literal> denotes
+ EDDSA over Curve25519 with SHA-512.</para>
+
+ <para>Note that your authenticator may not support some algorithms.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--fido2-device=</option><replaceable>PATH</replaceable></term>
+
+ <listitem><para>Takes a path to a Linux <literal>hidraw</literal> device
+ (e.g. <filename>/dev/hidraw1</filename>), referring to a FIDO2 security token implementing the
+ <literal>hmac-secret</literal> 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.</para>
+
+ <para>Instead of a valid path to a FIDO2 <literal>hidraw</literal> device the special strings
+ <literal>list</literal> and <literal>auto</literal> may be specified. If <literal>list</literal> is
+ passed, a brief table of suitable discovered FIDO2 devices is shown. If <literal>auto</literal> 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.</para>
+
+ <para>Note that FIDO2 devices suitable for this option must implement the
+ <literal>hmac-secret</literal> 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.</para>
+
+ <para>The FIDO2 device may be subsequently removed by setting the device path to an empty string
+ (e.g. <command>homectl update $USER --fido2-device=""</command>).</para>
+
+ <para>Note that many hardware security tokens implement both FIDO2 and PKCS#11/PIV (and thus may be
+ used with either <option>--fido2-device=</option> or <option>--pkcs11-token-uri=</option>), for a
+ discussion see above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--fido2-with-client-pin=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>When enrolling a FIDO2 security token, controls whether to require the user to enter
+ a PIN when unlocking the account (the FIDO2 <literal>clientPin</literal> feature). Defaults to
+ <literal>yes</literal>. (Note: this setting is without effect if the security token does not support
+ the <literal>clientPin</literal> feature at all, or does not allow enabling or disabling
+ it.)</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--fido2-with-user-presence=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>When enrolling a FIDO2 security token, controls whether to require the user to
+ verify presence (tap the token, the FIDO2 <literal>up</literal> feature) when unlocking the account.
+ Defaults to <literal>yes</literal>. (Note: this setting is without effect if the security token does not support
+ the <literal>up</literal> feature at all, or does not allow enabling or disabling it.)
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--fido2-with-user-verification=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>When enrolling a FIDO2 security token, controls whether to require user verification
+ when unlocking the account (the FIDO2 <literal>uv</literal> feature). Defaults to
+ <literal>no</literal>. (Note: this setting is without effect if the security token does not support
+ the <literal>uv</literal> feature at all, or does not allow enabling or disabling it.)</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--recovery-key=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--locked=</option><replaceable>BOOLEAN</replaceable></term>
+
+ <listitem><para>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).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--not-before=</option><replaceable>TIMESTAMP</replaceable></term>
+ <term><option>--not-after=</option><replaceable>TIMESTAMP</replaceable></term>
+
+ <listitem><para>These options take a timestamp string, in the format documented in
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry> and
+ configures points in time before and after logins into this account are not
+ permitted.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--rate-limit-interval=</option><replaceable>SECS</replaceable></term>
+ <term><option>--rate-limit-burst=</option><replaceable>NUMBER</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--password-hint=</option><replaceable>TEXT</replaceable></term>
+
+ <listitem><para>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: <option>--password-hint="My first pet's name"</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--enforce-password-policy=</option><replaceable>BOOL</replaceable></term>
+ <term><option>-P</option></term>
+
+ <listitem><para>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. <option>-P</option> is short for
+ <option>---enforce-password-policy=no</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--password-change-now=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>Takes a boolean argument. If true the user is asked to change their password on next
+ login.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--password-change-min=</option><replaceable>TIME</replaceable></term>
+ <term><option>--password-change-max=</option><replaceable>TIME</replaceable></term>
+ <term><option>--password-change-warn=</option><replaceable>TIME</replaceable></term>
+ <term><option>--password-change-inactive=</option><replaceable>TIME</replaceable></term>
+
+ <listitem><para>Each of these options takes a time span specification as argument (in the syntax
+ documented in
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>) and
+ configures various aspects of the user's password expiration policy. Specifically,
+ <option>--password-change-min=</option> 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. <option>--password-change-max=</option>
+ 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.
+ <option>--password-change-warn=</option> specifies how much earlier than then the time configured
+ with <option>--password-change-max=</option> the user is warned at login to change their password as
+ it will expire soon. Finally <option>--password-change-inactive=</option> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--disk-size=</option><replaceable>BYTES</replaceable></term>
+ <listitem><para>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 <literal>min</literal> or
+ <literal>max</literal>, and configures the disk space to assign to the user. If a percentage value is
+ specified (i.e. the argument suffixed with <literal>%</literal>) it is taken relative to the
+ available disk space of the backing file system. If specified as <literal>min</literal> assigns the
+ minimal disk space permitted by the constraints of the backing file system and other limits, when
+ specified as <literal>max</literal> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--access-mode=</option><replaceable>MODE</replaceable></term>
+
+ <listitem><para>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:
+ <option>--access-mode=0700</option></para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--umask=</option><replaceable>MASK</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--nice=</option><replaceable>NICE</replaceable></term>
+
+ <listitem><para>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).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--rlimit=</option><replaceable>LIMIT</replaceable>=<replaceable>VALUE</replaceable><optional>:<replaceable>VALUE</replaceable></optional></term>
+
+ <listitem><para>Allows configuration of resource limits for processes of this user, see <citerefentry
+ project='man-pages'><refentrytitle>getrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details. Takes a resource limit name (e.g. <literal>LIMIT_NOFILE</literal>) 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--tasks-max=</option><replaceable>TASKS</replaceable></term>
+
+ <listitem><para>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
+ <citerefentry project='man-pages'><refentrytitle>su</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ or a similar tool. Use <option>--rlimit=LIMIT_NPROC=</option> 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 <varname>TasksMax=</varname> setting of the per-user systemd slice unit
+ <filename>user-$UID.slice</filename>. See
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for further details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--memory-high=</option><replaceable>BYTES</replaceable></term>
+ <term><option>--memory-max=</option><replaceable>BYTES</replaceable></term>
+
+ <listitem><para>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
+ <varname>MemoryHigh=</varname> and <varname>MemoryMax=</varname> settings of the per-user systemd
+ slice unit <filename>user-$UID.slice</filename>. See
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for further details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--cpu-weight=</option><replaceable>WEIGHT</replaceable></term>
+ <term><option>--io-weight=</option><replaceable>WEIGHT</replaceable></term>
+
+ <listitem><para>Set CPU and IO scheduling weights of the processes of the user, including those of
+ processes forked off by the user that changed user credentials. Takes a numeric value in the range
+ 1…10000. This controls the <varname>CPUWeight=</varname> and <varname>IOWeight=</varname> settings of
+ the per-user systemd slice unit <filename>user-$UID.slice</filename>. See
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for further details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--storage=</option><replaceable>STORAGE</replaceable></term>
+
+ <listitem><para>Selects the storage mechanism to use for this home directory. Takes one of
+ <literal>luks</literal>, <literal>fscrypt</literal>, <literal>directory</literal>,
+ <literal>subvolume</literal>, <literal>cifs</literal>. For details about these mechanisms, see
+ above. If a new home directory is created and the storage type is not specifically specified,
+ <citerefentry><refentrytitle>homed.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ defines which default storage to use.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--image-path=</option><replaceable>PATH</replaceable></term>
+
+ <listitem><para>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 <filename>/home/</filename> or any other accessible filesystem). When
+ unspecified defaults to <filename>/home/$USER.home</filename> when LUKS storage is used and
+ <filename>/home/$USER.homedir</filename> for the other storage mechanisms. Not defined for the
+ <literal>cifs</literal> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--drop-caches=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--fs-type=</option><replaceable>TYPE</replaceable></term>
+
+ <listitem><para>When LUKS2 storage is used configures the file system type to use inside the home
+ directory LUKS2 container. One of <literal>btrfs</literal>, <literal>ext4</literal>,
+ <literal>xfs</literal>. If not specified
+ <citerefentry><refentrytitle>homed.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ defines which default file system type to use. Note that <literal>xfs</literal> is not recommended as
+ its support for file system resizing is too limited.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--luks-discard=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>When LUKS2 storage is used configures whether to enable the
+ <literal>discard</literal> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--luks-offline-discard=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>Similar to <option>--luks-discard=</option>, controls the trimming of the file
+ system. However, while <option>--luks-discard=</option> controls what happens when the home directory
+ is active, <option>--luks-offline-discard=</option> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--luks-extra-mount-options=</option><replaceable>OPTIONS</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--luks-cipher=</option><replaceable>CIPHER</replaceable></term>
+ <term><option>--luks-cipher-mode=</option><replaceable>MODE</replaceable></term>
+ <term><option>--luks-volume-key-size=</option><replaceable>BYTES</replaceable></term>
+ <term><option>--luks-pbkdf-type=</option><replaceable>TYPE</replaceable></term>
+ <term><option>--luks-pbkdf-hash-algorithm=</option><replaceable>ALGORITHM</replaceable></term>
+ <term><option>--luks-pbkdf-time-cost=</option><replaceable>SECONDS</replaceable></term>
+ <term><option>--luks-pbkdf-memory-cost=</option><replaceable>BYTES</replaceable></term>
+ <term><option>--luks-pbkdf-parallel-threads=</option><replaceable>THREADS</replaceable></term>
+ <term><option>--luks-sector-size=</option><replaceable>BYTES</replaceable></term>
+
+ <listitem><para>Configures various cryptographic parameters for the LUKS2 storage mechanism. See
+ <citerefentry
+ project='man-pages'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for details on the specific attributes.</para>
+
+ <para>Note that <command>homectl</command> uses bytes for key size, like
+ <filename>/proc/crypto</filename>, but <citerefentry
+ project='man-pages'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ uses bits.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--auto-resize-mode=</option></term>
+
+ <listitem><para>Configures whether to automatically grow and/or shrink the backing file system on
+ login and logout. Takes one of the strings <literal>off</literal>, <literal>grow</literal>,
+ <literal>shrink-and-grow</literal>. 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 <literal>shrink-and-grow</literal>, if LUKS2/btrfs is used, otherwise is
+ off. If set to <literal>off</literal> no automatic shrinking/growing during login or logout is
+ done. If set to <literal>grow</literal> the home area is grown to the size configured via
+ <option>--disk-size=</option> should it currently be smaller. If it already matches the configured
+ size or is larger no operation is executed. If set to <literal>shrink-and-grow</literal> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--rebalance-weight=</option></term>
+
+ <listitem><para>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 <literal>off</literal>. 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
+ <literal>off</literal> no automatic free space distribution is done for this home area. Note that
+ resizing the home area explicitly (with <command>homectl resize</command> see below) will implicitly
+ turn off the automatic rebalancing. To reenable the automatic rebalancing use
+ <option>--rebalance-weight=</option> with an empty parameter.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--nosuid=</option><replaceable>BOOL</replaceable></term>
+ <term><option>--nodev=</option><replaceable>BOOL</replaceable></term>
+ <term><option>--noexec=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>Configures the <literal>nosuid</literal>, <literal>nodev</literal> and
+ <literal>noexec</literal> mount options for the home directories. By default <literal>nodev</literal>
+ and <literal>nosuid</literal> are on, while <literal>noexec</literal> is off. For details about these
+ mount options see <citerefentry
+ project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--cifs-domain=</option><replaceable>DOMAIN</replaceable></term>
+ <term><option>--cifs-user-name=</option><replaceable>USER</replaceable></term>
+ <term><option>--cifs-service=</option><replaceable>SERVICE</replaceable></term>
+ <term><option>--cifs-extra-mount-options=</option><replaceable>OPTIONS</replaceable></term>
+
+ <listitem><para>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 <literal>cifs</literal> storage is selected. The file share should be specified in format
+ <literal>//<replaceable>host</replaceable>/<replaceable>share</replaceable>/<replaceable>directory/…</replaceable></literal>. The
+ directory part is optional — if not specified the home directory will be placed in the top-level
+ directory of the share. The <option>--cifs-extra-mount-options=</option> setting allows specifying
+ additional mount options when mounting the share, see <citerefentry
+ project='man-pages'><refentrytitle>mount.cifs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--stop-delay=</option><replaceable>SECS</replaceable></term>
+
+ <listitem><para>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
+ <citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> (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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--kill-processes=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>Configures whether to kill all processes of the user on logout. The default is
+ configured in
+ <citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--auto-login=</option><replaceable>BOOL</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Commands</title>
+
+ <para>The following commands are understood:</para>
+
+ <variablelist>
+
+ <varlistentry>
+ <term><command>list</command></term>
+
+ <listitem><para>List all home directories (along with brief details) currently managed by
+ <filename>systemd-homed.service</filename>. 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
+ <filename>/etc/passwd</filename>.)</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>activate</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
+
+ <listitem><para>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
+ <filename>/home/$USER</filename>). Note that any home activated this way stays active indefinitely,
+ until it is explicitly deactivated again (with <command>deactivate</command>, see below), or the user
+ logs in and out again and it thus is deactivated due to the automatic deactivation-on-logout
+ logic.</para>
+
+ <para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>deactivate</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
+
+ <listitem><para>Deactivate one or more home directories. This undoes the effect of
+ <command>activate</command>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>inspect</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
+
+ <listitem><para>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 <option>--json=</option> to show the detailed JSON user
+ record instead, possibly combined with <option>--export-format=</option> to suppress certain aspects
+ of the output.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>authenticate</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>create</command> <replaceable>USER</replaceable></term>
+ <term><command>create</command> <option>--identity=</option><replaceable>PATH</replaceable> <optional><replaceable>USER</replaceable></optional></term>
+
+ <listitem><para>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.</para>
+
+ <para>The specified user name should follow the strict syntax described on <ulink
+ url="https://systemd.io/USER_NAMES">User/Group Name Syntax</ulink>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>remove</command> <replaceable>USER</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>update</command> <replaceable>USER</replaceable></term>
+ <term><command>update</command> <option>--identity=</option><replaceable>PATH</replaceable> <optional><replaceable>USER</replaceable></optional></term>
+
+ <listitem><para>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 <option>--identity=</option> option.</para>
+
+ <para>Note that changes to user records not signed by a cryptographic private key available locally
+ are not permitted, unless <option>--identity=</option> is used with a user record that is already
+ correctly signed by a recognized private key.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>passwd</command> <replaceable>USER</replaceable></term>
+
+ <listitem><para>Change the password of the specified home directory/user account.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>resize</command> <replaceable>USER</replaceable> <replaceable>BYTES</replaceable></term>
+
+ <listitem><para>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 <literal>ext4</literal> 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 <literal>xfs</literal> is used inside of the LUKS2 volume the
+ home directory may not be shrunk whatsoever. On all three of <literal>ext4</literal>,
+ <literal>xfs</literal> and <literal>btrfs</literal> 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
+ <literal>subvolume</literal>, <literal>directory</literal>, <literal>fscrypt</literal> 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 <literal>min</literal> and
+ <literal>max</literal> 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>lock</command> <replaceable>USER</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>unlock</command> <replaceable>USER</replaceable></term>
+
+ <listitem><para>Resume access to the user's home directory again, undoing the effect of
+ <command>lock</command> above. This requires authentication of the user, as the cryptographic keys
+ required for access to the home directory need to be reacquired.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>lock-all</command></term>
+
+ <listitem><para>Execute the <command>lock</command> command on all suitable home directories at
+ once. This operation is generally executed on system suspend (i.e. by <command>systemctl
+ suspend</command> and related commands), to ensure all active user's cryptographic keys for accessing
+ their home directories are removed from memory.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>deactivate-all</command></term>
+
+ <listitem><para>Execute the <command>deactivate</command> command on all active home directories at
+ once. This operation is generally executed on system shut down (i.e. by <command>systemctl
+ poweroff</command> and related commands), to ensure all active user's home directories are fully
+ deactivated before <filename>/home/</filename> and related file systems are unmounted.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>with</command> <replaceable>USER</replaceable> <replaceable>COMMAND…</replaceable></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><command>rebalance</command></term>
+
+ <listitem><para>Rebalance free disk space between active home areas and the backing storage. See
+ <option>--rebalance-weight=</option> 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.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Exit status</title>
+
+ <para>On success, 0 is returned, a non-zero failure code otherwise.</para>
+
+ <para>When a command is invoked with <command>with</command>, the exit status of the child is
+ propagated. Effectively, <command>homectl</command> will exit without error if the command is
+ successfully invoked <emphasis>and</emphasis> finishes successfully.</para>
+ </refsect1>
+
+ <xi:include href="common-variables.xml" />
+
+ <refsect1>
+ <title>Examples</title>
+
+ <example>
+ <title>Create a user <literal>waldo</literal> in the administrator group <literal>wheel</literal>, and
+ assign 500 MiB disk space to them.</title>
+
+ <programlisting>homectl create waldo --real-name="Waldo McWaldo" -G wheel --disk-size=500M</programlisting>
+ </example>
+
+ <example>
+ <title>Create a user <literal>wally</literal> on a USB stick, and assign a maximum of 500 concurrent
+ tasks to them.</title>
+
+ <programlisting>homectl create wally --real-name="Wally McWally" --image-path=/dev/disk/by-id/usb-SanDisk_Ultra_Fit_476fff954b2b5c44-0:0 --tasks-max=500</programlisting>
+ </example>
+
+ <example>
+ <title>Change nice level of user <literal>odlaw</literal> to +5 and make sure the environment variable
+ <varname>$SOME</varname> is set to the string <literal>THING</literal> for them on login.</title>
+
+ <programlisting>homectl update odlaw --nice=5 --setenv=SOME=THING</programlisting>
+ </example>
+
+ <example>
+ <title>Set up authentication with a YubiKey security token using PKCS#11/PIV:</title>
+
+ <programlisting># 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</programlisting>
+ </example>
+
+ <example>
+ <title>Set up authentication with a FIDO2 security token:</title>
+
+ <programlisting># Allow a FIDO2 security token to unlock the account of user 'nihilbaxter'.
+homectl update nihilbaxter --fido2-device=auto</programlisting>
+ </example>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-homed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>homed.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>