man/homectl.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="homectl" conditional='ENABLE_HOMED'
   7     xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>homectl</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>homectl</refentrytitle>
  16     <manvolnum>1</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>homectl</refname>
  21     <refname>systemd-homed-firstboot.service</refname>
  22     <refpurpose>Create, remove, change or inspect home directories</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <cmdsynopsis>
  27       <command>homectl</command>
  28       <arg choice="opt" rep="repeat">OPTIONS</arg>
  29       <arg choice="req">COMMAND</arg>
  30       <arg choice="opt" rep="repeat">NAME</arg>
  31     </cmdsynopsis>
  32   </refsynopsisdiv>
  33
  34   <refsect1>
  35     <title>Description</title>
  36
  37     <para><command>homectl</command> may be used to create, remove, change or inspect a user's home
  38     directory. It's primarily a command interfacing with
  39     <citerefentry><refentrytitle>systemd-homed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  40     which manages home directories of users.</para>
  41
  42     <para>Home directories managed by <filename>systemd-homed.service</filename> are self-contained, and thus
  43     include the user's full metadata record in the home's data storage itself, making them easy to migrate
  44     between machines. In particular, a home directory describes a matching user record, and every user record
  45     managed by <filename>systemd-homed.service</filename> also implies existence and encapsulation of a home
  46     directory. The user account and home directory become the same concept.</para>
  47
  48     <para>The following backing storage mechanisms are supported:</para>
  49
  50     <itemizedlist>
  51       <listitem><para>An individual LUKS2 encrypted loopback file for a user, stored in
  52       <filename>/home/*.home</filename>. At login the file system contained in this files is mounted, after
  53       the LUKS2 encrypted volume has been attached. The user's password is identical to the encryption
  54       passphrase of the LUKS2 volume. Access to data without preceding user authentication is thus not
  55       possible, even for the system administrator. This storage mechanism provides the strongest data
  56       security and is thus recommended.</para></listitem>
  57
  58       <listitem><para>Similar, but the LUKS2 encrypted file system is located on regular block device, such
  59       as a USB storage stick. In this mode home directories and all data they include are nicely migratable
  60       between machines, simply by plugging the USB stick into different systems at different
  61       times.</para></listitem>
  62
  63       <listitem><para>An encrypted directory using <literal>fscrypt</literal> on file systems that support it
  64       (at the moment this is primarily <literal>ext4</literal>), located in
  65       <filename>/home/*.homedir</filename>. This mechanism also provides encryption, but substantially
  66       weaker than LUKS2, as most file system metadata is unprotected. Moreover
  67       it currently does not support changing user passwords once the home directory has been
  68       created.</para></listitem>
  69
  70       <listitem><para>A <literal>btrfs</literal> subvolume for each user, also located in
  71       <filename>/home/*.homedir</filename>. This provides no encryption, but good quota
  72       support.</para></listitem>
  73
  74       <listitem><para>A regular directory for each user, also located in
  75       <filename>/home/*.homedir</filename>. This provides no encryption, but is a suitable fallback
  76       available on all machines, even where LUKS2, <literal>fscrypt</literal> or <literal>btrfs</literal>
  77       support is not available.</para></listitem>
  78
  79       <listitem><para>An individual Windows file share (CIFS) for each user.</para></listitem>
  80     </itemizedlist>
  81
  82     <para>Note that <filename>systemd-homed.service</filename> and <command>homectl</command> will not manage
  83     "classic" UNIX user accounts as created with <citerefentry
  84     project='man-pages'><refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum></citerefentry> or
  85     similar tools. In particular, this functionality is not suitable for managing system users (i.e. users
  86     with a UID below 1000) but is exclusive to regular ("human") users.</para>
  87
  88     <para>Note that users/home directories managed via <command>systemd-homed.service</command> do not show
  89     up in <filename>/etc/passwd</filename> and similar files, they are synthesized via glibc NSS during
  90     runtime. They are thus resolvable and may be enumerated via the <citerefentry
  91     project='man-pages'><refentrytitle>getent</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  92     tool.</para>
  93
  94     <para>This tool interfaces directly with <filename>systemd-homed.service</filename>, and may execute
  95     specific commands on the home directories it manages. Since every home directory managed that way also
  96     defines a JSON user and group record these home directories may also be inspected and enumerated via
  97     <citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
  98
  99     <para>Home directories managed by <filename>systemd-homed.service</filename> are usually in one of two
 100     states, or in a transition state between them: when <literal>active</literal> they are unlocked and
 101     mounted, and thus accessible to the system and its programs; when <literal>inactive</literal> they are
 102     not mounted and thus not accessible. Activation happens automatically at login of the user and usually
 103     can only complete after a password (or other authentication token) has been supplied. Deactivation
 104     happens after the user fully logged out. A home directory remains active as long as the user is logged in
 105     at least once, i.e. has at least one login session. When the user logs in a second time simultaneously
 106     the home directory remains active. It is deactivated only after the last of the user's sessions
 107     ends.</para>
 108   </refsect1>
 109
 110   <refsect1>
 111     <title>Options</title>
 112
 113     <para>The following general options are understood (further options that control the various properties
 114     of user records managed by <filename>systemd-homed.service</filename> are documented further
 115     down):</para>
 116
 117     <variablelist>
 118
 119       <varlistentry>
 120         <term><option>--identity=<replaceable>FILE</replaceable></option></term>
 121
 122         <listitem><para>Read the user's JSON record from the specified file. If passed as
 123         <literal>-</literal> read the user record from standard input. The supplied JSON object must follow
 124         the structure documented in <ulink url="https://systemd.io/USER_RECORD">JSON User Records</ulink>.
 125         This option may be used in conjunction with the <command>create</command> and
 126         <command>update</command> commands (see below), where it allows configuring the user record in JSON
 127         as-is, instead of setting the individual user record properties (see below).</para>
 128
 129         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 130       </varlistentry>
 131
 132       <varlistentry>
 133         <term><option>--json=<replaceable>FORMAT</replaceable></option></term>
 134         <term><option>-j</option></term>
 135
 136         <listitem><para>Controls whether to output the user record in JSON format, if the
 137         <command>inspect</command> command (see below) is used. Takes one of <literal>pretty</literal>,
 138         <literal>short</literal> or <literal>off</literal>. If <literal>pretty</literal> human-friendly
 139         whitespace and newlines are inserted in the output to make the JSON data more readable. If
 140         <literal>short</literal> all superfluous whitespace is suppressed. If <literal>off</literal> (the
 141         default) the user information is not shown in JSON format but in a friendly human readable formatting
 142         instead. The <option>-j</option> option picks <literal>pretty</literal> when run interactively and
 143         <literal>short</literal> otherwise.</para>
 144
 145         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 146       </varlistentry>
 147
 148       <varlistentry>
 149         <term><option>--export-format=<replaceable>FORMAT</replaceable></option></term>
 150         <term><option>-E</option></term>
 151         <term><option>-EE</option></term>
 152
 153         <listitem><para>When used with the <command>inspect</command> verb in JSON mode (see above) may be
 154         used to suppress certain aspects of the JSON user record on output. Specifically, if
 155         <literal>stripped</literal> format is used the binding and runtime fields of the record are
 156         removed. If <literal>minimal</literal> format is used the cryptographic signature is removed too. If
 157         <literal>full</literal> format is used the full JSON record is shown (this is the default). This
 158         option is useful for copying an existing user record to a different system in order to create a
 159         similar user there with the same settings. Specifically: <command>homectl inspect -EE | ssh
 160         root@othersystem homectl create -i-</command> may be used as simple command line for replicating a
 161         user on another host. <option>-E</option> is equivalent to <option>-j --export-format=stripped</option>,
 162         <option>-EE</option> to <option>-j --export-format=minimal</option>. Note that when replicating user
 163         accounts user records acquired in <literal>stripped</literal> mode will retain the original
 164         cryptographic signatures and thus may only be modified when the private key to update them is available
 165         on the destination machine. When replicating users in <literal>minimal</literal> mode, the signature
 166         is removed during the replication and thus the record will be implicitly signed with the key of the destination
 167         machine and may be updated there without any private key replication.</para>
 168
 169         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 170       </varlistentry>
 171
 172       <varlistentry>
 173         <term><option>--offline</option></term>
 174
 175         <listitem><para>Do not attempt to update the copy of the user record and blob directory that is embedded inside
 176         of the home area. This allows for operation on home areas that are absent, or without needing to authenticate as
 177         the user being modified.</para>
 178
 179         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
 180       </varlistentry>
 181
 182       <xi:include href="user-system-options.xml" xpointer="host" />
 183       <xi:include href="user-system-options.xml" xpointer="machine" />
 184
 185       <xi:include href="standard-options.xml" xpointer="no-pager" />
 186       <xi:include href="standard-options.xml" xpointer="no-legend" />
 187       <xi:include href="standard-options.xml" xpointer="no-ask-password" />
 188       <xi:include href="standard-options.xml" xpointer="help" />
 189       <xi:include href="standard-options.xml" xpointer="version" />
 190     </variablelist>
 191   </refsect1>
 192
 193   <refsect1>
 194     <title>User Record Properties</title>
 195
 196     <para>The following options control various properties of the user records/home directories that
 197     <filename>systemd-homed.service</filename> manages. These switches may be used in conjunction with the
 198     <command>create</command> and <command>update</command> commands for configuring various aspects of the
 199     home directory and the user account:</para>
 200
 201     <variablelist>
 202
 203       <varlistentry>
 204         <term><option>--real-name=<replaceable>NAME</replaceable></option></term>
 205         <term><option>-c</option> <replaceable>NAME</replaceable></term>
 206
 207         <listitem><para>The real name for the user. This corresponds with the GECOS field on classic UNIX NSS
 208         records.</para>
 209
 210         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 211       </varlistentry>
 212
 213       <varlistentry>
 214         <term><option>--realm=<replaceable>REALM</replaceable></option></term>
 215
 216         <listitem><para>The realm for the user. The realm associates a user with a specific organization or
 217         installation, and allows distinguishing users of the same name defined in different contexts. The
 218         realm can be any string that also qualifies as valid DNS domain name, and it is recommended to use
 219         the organization's or installation's domain name for this purpose, but this is not enforced nor
 220         required. On each system only a single user of the same name may exist, and if a user with the same
 221         name and realm is seen it is assumed to refer to the same user while a user with the same name but
 222         different realm is considered a different user. Note that this means that two users sharing the same
 223         name but with distinct realms are not allowed on the same system. Assigning a realm to a user is
 224         optional.</para>
 225
 226         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 227       </varlistentry>
 228
 229       <varlistentry>
 230         <term><option>--email-address=<replaceable>EMAIL</replaceable></option></term>
 231
 232         <listitem><para>Takes an electronic mail address to associate with the user. On log-in the
 233         <varname>$EMAIL</varname> environment variable is initialized from this value.</para>
 234
 235         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 236       </varlistentry>
 237
 238       <varlistentry>
 239         <term><option>--location=<replaceable>TEXT</replaceable></option></term>
 240
 241         <listitem><para>Takes location specification for this user. This is free-form text, which might or
 242         might not be usable by geo-location applications. Example: <option>--location="Berlin,
 243         Germany"</option> or <option>--location="Basement, Room 3a"</option></para>
 244
 245         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 246       </varlistentry>
 247
 248       <varlistentry>
 249         <term><option>--icon-name=<replaceable>ICON</replaceable></option></term>
 250
 251         <listitem><para>Takes an icon name to associate with the user, following the scheme defined by the <ulink
 252         url="https://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">Icon Naming
 253         Specification</ulink>.</para>
 254
 255         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 256       </varlistentry>
 257
 258       <varlistentry>
 259         <term><option>--home-dir=<replaceable>PATH</replaceable></option></term>
 260         <term><option>-d<replaceable>PATH</replaceable></option></term>
 261
 262         <listitem><para>Takes a path to use as home directory for the user. Note that this is the directory
 263         the user's home directory is mounted to while the user is logged in. This is not where the user's
 264         data is actually stored, see <option>--image-path=</option> for that. If not specified defaults to
 265         <filename>/home/$USER</filename>.</para>
 266
 267         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 268       </varlistentry>
 269
 270       <varlistentry>
 271         <term><option>--uid=<replaceable>UID</replaceable></option></term>
 272
 273         <listitem><para>Takes a preferred numeric UNIX UID to assign this user. If a user is to be created
 274         with the specified UID and it is already taken by a different user on the local system then creation
 275         of the home directory is refused. Note though, if after creating the home directory it is used on a
 276         different system and the configured UID is taken by another user there, then
 277         <command>systemd-homed</command> may assign the user a different UID on that system. The specified
 278         UID must be outside of the system user range. It is recommended to use the 60001…60513 UID range for
 279         this purpose. If not specified, the UID is automatically picked. If the home directory is found to be
 280         owned by a different UID when logging in, the home directory and everything underneath it will have
 281         its ownership changed automatically before login completes.</para>
 282
 283         <para>Note that changing this option for existing home directories generally has no effect on home
 284         directories that already have been registered locally (have a local <emphasis>binding</emphasis>), as
 285         the UID used for an account on the local system is determined when the home directory is first
 286         activated on it, and then remains in effect until the home directory is removed.</para>
 287
 288         <para>Note that users managed by <command>systemd-homed</command> always have a matching group
 289         associated with the same name as well as a GID matching the UID of the user. Thus, configuring the
 290         GID separately is not permitted.</para>
 291
 292         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 293       </varlistentry>
 294
 295       <varlistentry>
 296         <term><option>--member-of=<replaceable>GROUP</replaceable></option></term>
 297         <term><option>-G</option> <replaceable>GROUP</replaceable></term>
 298
 299         <listitem><para>Takes a comma-separated list of auxiliary UNIX groups this user shall belong
 300         to. Example: <option>--member-of=wheel</option> to provide the user with administrator
 301         privileges. Note that <command>systemd-homed</command> does not manage any groups besides a group
 302         matching the user in name and numeric UID/GID. Thus any groups listed here must be registered
 303         independently, for example with <citerefentry
 304         project='man-pages'><refentrytitle>groupadd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 305         Any non-existent groups are ignored. This option may be used more than once, in which case all
 306         specified group lists are combined. If the user is currently a member of a group which is not listed,
 307         the user will be removed from the group.</para>
 308
 309         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 310       </varlistentry>
 311
 312       <varlistentry>
 313         <term><option>--capability-bounding-set=<replaceable>CAPABILITIES</replaceable></option></term>
 314         <term><option>--capability-ambient-set=<replaceable>CAPABILITIES</replaceable></option></term>
 315
 316         <listitem><para>These options take a space separated list of process capabilities
 317         (e.g. <constant>CAP_WAKE_ALARM</constant>, <constant>CAP_BLOCK_SUSPEND</constant>, …) that shall be
 318         set in the capability bounding and ambient sets for all the user's sessions. See <citerefentry
 319         project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 320         for details on the capabilities concept. These options may be used more than once, in which case the
 321         specified lists are combined. If the parameter begins with a <literal>~</literal> character the
 322         effect is inverted: the specified capability is dropped from the specific set.</para>
 323
 324         <xi:include href="version-info.xml" xpointer="v254"/></listitem>
 325       </varlistentry>
 326
 327       <varlistentry>
 328         <term><option>--skel=<replaceable>PATH</replaceable></option></term>
 329
 330         <listitem><para>Takes a file system path to a directory. Specifies the skeleton directory to
 331         initialize the home directory with. All files and directories in the specified path are copied into
 332         any newly create home directory. If not specified defaults to <filename>/etc/skel/</filename>.
 333         </para>
 334
 335         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 336       </varlistentry>
 337
 338       <varlistentry>
 339         <term><option>--shell=<replaceable>SHELL</replaceable></option></term>
 340
 341         <listitem><para>Takes a file system path. Specifies the shell binary to execute on terminal
 342         logins. If not specified defaults to <filename>/bin/bash</filename>.</para>
 343
 344         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 345       </varlistentry>
 346
 347       <varlistentry>
 348         <term><option>--setenv=<replaceable>VARIABLE</replaceable>[=<replaceable>VALUE</replaceable>]</option></term>
 349
 350         <listitem><para>Takes an environment variable assignment to set for all user processes. May be used
 351         multiple times to set multiple environment variables. When <literal>=</literal> and
 352         <replaceable>VALUE</replaceable> are omitted, the value of the variable with the same name in the
 353         program environment will be used.</para>
 354
 355         <para>Note that a number of other settings also result in environment variables to be set for the
 356         user, including <option>--email=</option>, <option>--timezone=</option> and
 357         <option>--language=</option>.</para>
 358
 359         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 360       </varlistentry>
 361
 362       <varlistentry>
 363         <term><option>--timezone=<replaceable>TIMEZONE</replaceable></option></term>
 364
 365         <listitem><para>Takes a time zone location name that sets the timezone for the specified user. When
 366         the user logs in the <varname>$TZ</varname> environment variable is initialized from this
 367         setting. Example: <option>--timezone=Europe/Amsterdam</option> will result in the environment
 368         variable <literal>TZ=:Europe/Amsterdam</literal>. (<literal>:</literal> is used intentionally as part
 369         of the timezone specification, see
 370         <citerefentry project='man-pages'><refentrytitle>tzset</refentrytitle><manvolnum>3</manvolnum></citerefentry>.)
 371         </para>
 372
 373         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 374       </varlistentry>
 375
 376       <varlistentry>
 377         <term><option>--language=<replaceable>LANG</replaceable></option></term>
 378
 379         <listitem><para>Takes a comma- or colon-separated list of languages preferred by the user, ordered
 380         by descending priority. The <varname>$LANG</varname> and <varname>$LANGUAGE</varname> environment
 381         variables are initialized from this value on login, and thus values suitible for these environment
 382         variables are accepted here, for example <option>--language=de_DE.UTF-8</option>. This option may
 383         be used more than once, in which case the language lists are concatenated.</para>
 384
 385         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 386       </varlistentry>
 387
 388       <varlistentry>
 389         <term><option>--ssh-authorized-keys=<replaceable>KEYS</replaceable></option></term>
 390         <listitem><para>Either takes a SSH authorized key line to associate with the user record or a
 391         <literal>@</literal> character followed by a path to a file to read one or more such lines from. SSH
 392         keys configured this way are made available to SSH to permit access to this home directory and user
 393         record. This option may be used more than once to configure multiple SSH keys.</para>
 394
 395         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 396       </varlistentry>
 397
 398       <varlistentry>
 399         <term><option>--pkcs11-token-uri=<replaceable>URI</replaceable></option></term>
 400         <listitem><para>Takes an RFC 7512 PKCS#11 URI referencing a security token (e.g. YubiKey or PIV
 401         smartcard) that shall be able to unlock the user account. The security token URI should reference a
 402         security token with exactly one pair of X.509 certificate and private key. A random secret key is
 403         then generated, encrypted with the public key of the X.509 certificate, and stored as part of the
 404         user record. At login time it is decrypted with the PKCS#11 module and then used to unlock the
 405         account and associated resources. See below for an example how to set up authentication with a
 406         security token.</para>
 407
 408         <para>Instead of a valid PKCS#11 URI, the special strings <literal>list</literal> and
 409         <literal>auto</literal> may be specified. If <literal>list</literal> is passed, a brief table of
 410         suitable, currently plugged in PKCS#11 hardware tokens is shown, along with their URIs. If
 411         <literal>auto</literal> is passed, a suitable PKCS#11 hardware token is automatically selected (this
 412         operation will fail if there isn't exactly one suitable token discovered). The latter is a useful
 413         shortcut for the most common case where a single PKCS#11 hardware token is plugged in.</para>
 414
 415         <para>Note that many hardware security tokens implement both PKCS#11/PIV and FIDO2 with the
 416         <literal>hmac-secret</literal> extension (for example: the YubiKey 5 series), as supported with the
 417         <option>--fido2-device=</option> option below. Both mechanisms are similarly powerful, though FIDO2
 418         is the more modern technology. PKCS#11/PIV tokens have the benefit of being recognizable before
 419         authentication and hence can be used for implying the user identity to use for logging in, which
 420         FIDO2 does not allow. PKCS#11/PIV devices generally require initialization (i.e. storing a
 421         private/public key pair on them, see example below) before they can be used; FIDO2 security tokens
 422         generally do not required that, and work out of the box.</para>
 423
 424         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 425       </varlistentry>
 426
 427       <varlistentry>
 428         <term><option>--fido2-credential-algorithm=<replaceable>STRING</replaceable></option></term>
 429         <listitem><para>Specify COSE algorithm used in credential generation. The default value is
 430         <literal>es256</literal>. Supported values are <literal>es256</literal>, <literal>rs256</literal>
 431         and <literal>eddsa</literal>.</para>
 432
 433         <para><literal>es256</literal> denotes ECDSA over NIST P-256 with SHA-256. <literal>rs256</literal>
 434         denotes 2048-bit RSA with PKCS#1.5 padding and SHA-256. <literal>eddsa</literal> denotes
 435         EDDSA over Curve25519 with SHA-512.</para>
 436
 437         <para>Note that your authenticator may choose not to support some algorithms.</para>
 438
 439         <xi:include href="version-info.xml" xpointer="v251"/></listitem>
 440       </varlistentry>
 441
 442       <varlistentry>
 443         <term><option>--fido2-device=<replaceable>PATH</replaceable></option></term>
 444
 445         <listitem><para>Takes a path to a Linux <literal>hidraw</literal> device
 446         (e.g. <filename>/dev/hidraw1</filename>), referring to a FIDO2 security token implementing the
 447         <literal>hmac-secret</literal> extension that shall be able to unlock the user account. A random salt
 448         value is generated on the host and passed to the FIDO2 device, which calculates a HMAC hash of the
 449         salt using an internal secret key. The result is then used as the key to unlock the user account. The
 450         random salt is included in the user record, so that whenever authentication is needed it can be
 451         passed to the FIDO2 token again.</para>
 452
 453         <para>Instead of a valid path to a FIDO2 <literal>hidraw</literal> device the special strings
 454         <literal>list</literal> and <literal>auto</literal> may be specified. If <literal>list</literal> is
 455         passed, a brief table of suitable discovered FIDO2 devices is shown. If <literal>auto</literal> is
 456         passed, a suitable FIDO2 token is automatically selected, if exactly one is discovered. The latter is
 457         a useful shortcut for the most common case where a single FIDO2 hardware token is plugged in.</para>
 458
 459         <para>Note that FIDO2 devices suitable for this option must implement the
 460         <literal>hmac-secret</literal> extension. Most current devices (such as the YubiKey 5 series) do. If
 461         the extension is not implemented the device cannot be used for unlocking home directories.</para>
 462
 463         <para>The FIDO2 device may be subsequently removed by setting the device path to an empty string
 464         (e.g. <command>homectl update $USER --fido2-device=""</command>).</para>
 465
 466         <para>Note that many hardware security tokens implement both FIDO2 and PKCS#11/PIV (and thus may be
 467         used with either <option>--fido2-device=</option> or <option>--pkcs11-token-uri=</option>), for a
 468         discussion see above.</para>
 469
 470         <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 471       </varlistentry>
 472
 473       <varlistentry>
 474         <term><option>--fido2-with-client-pin=<replaceable>BOOL</replaceable></option></term>
 475
 476         <listitem><para>When enrolling a FIDO2 security token, controls whether to require the user to enter
 477         a PIN when unlocking the account (the FIDO2 <literal>clientPin</literal> feature). Defaults to
 478         <literal>yes</literal>. (Note: this setting is without effect if the security token does not support
 479         the <literal>clientPin</literal> feature at all, or does not allow enabling or disabling
 480         it.)</para>
 481
 482         <xi:include href="version-info.xml" xpointer="v249"/></listitem>
 483       </varlistentry>
 484
 485       <varlistentry>
 486         <term><option>--fido2-with-user-presence=<replaceable>BOOL</replaceable></option></term>
 487
 488         <listitem><para>When enrolling a FIDO2 security token, controls whether to require the user to
 489         verify presence (tap the token, the FIDO2 <literal>up</literal> feature) when unlocking the account.
 490         Defaults to <literal>yes</literal>. (Note: this setting is without effect if the security token does not support
 491         the <literal>up</literal> feature at all, or does not allow enabling or disabling it.)
 492         </para>
 493
 494         <xi:include href="version-info.xml" xpointer="v249"/></listitem>
 495       </varlistentry>
 496
 497       <varlistentry>
 498         <term><option>--fido2-with-user-verification=<replaceable>BOOL</replaceable></option></term>
 499
 500         <listitem><para>When enrolling a FIDO2 security token, controls whether to require user verification
 501         when unlocking the account (the FIDO2 <literal>uv</literal> feature). Defaults to
 502         <literal>no</literal>. (Note: this setting is without effect if the security token does not support
 503         the <literal>uv</literal> feature at all, or does not allow enabling or disabling it.)</para>
 504
 505         <xi:include href="version-info.xml" xpointer="v249"/></listitem>
 506       </varlistentry>
 507
 508       <varlistentry>
 509         <term><option>--recovery-key=<replaceable>BOOL</replaceable></option></term>
 510
 511         <listitem><para>Accepts a boolean argument. If enabled a recovery key is configured for the
 512         account. A recovery key is a computer generated access key that may be used to regain access to an
 513         account if the password has been forgotten or the authentication token lost. The key is generated and
 514         shown on screen, and should be printed or otherwise transferred to a secure location. A recovery key
 515         may be entered instead of a regular password to unlock the account.</para>
 516
 517         <xi:include href="version-info.xml" xpointer="v247"/></listitem>
 518       </varlistentry>
 519
 520     <varlistentry>
 521         <term><option>--blob=<replaceable>PATH</replaceable></option></term>
 522         <term><option>-b</option> <replaceable>PATH</replaceable></term>
 523         <term><option>--blob=<replaceable>FILENAME</replaceable>=<replaceable>PATH</replaceable></option></term>
 524         <term><option>-b</option> <replaceable>FILENAME</replaceable>=<replaceable>PATH</replaceable></term>
 525
 526         <listitem><para>Accepts either a directory path, or a file name followed by a file path. If just a
 527         directory path is specified, then the user's entire blob directory is replaced the specified path.
 528         Note that this replacement is performed before per-file manipulations are applied, which means these per-file
 529         manipulations will be applied on top of the specified directory. If a filename and file path are specified, then
 530         the single specified blob file will be overwritten with the specified path. If completely blank, the entire blob
 531         directory is emptied out (which also resets all previous blob-related flags up to this point). If a filename is
 532         specified but the corresponding path is blank, that single file will be deleted from the blob directory. All changes
 533         are performed in temporary copies of the specified files in directories, which means that the originals specified on
 534         the command line are not modified. See <ulink url="https://systemd.io/USER_RECORD_BLOB_DIRS">User Record Blob Directories</ulink>
 535         for more information about blob directories.</para>
 536
 537         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
 538       </varlistentry>
 539
 540     <varlistentry>
 541         <term><option>--avatar=<replaceable>PATH</replaceable></option></term>
 542         <term><option>--login-background=<replaceable>PATH</replaceable></option></term>
 543
 544         <listitem><para>Accept a file path. If set, the specified file is used to overwrite the
 545         corresponding file in the user's blob directory. If blank, the corresponding file is deleted
 546         from the blob directory. Essentially, these options are shortcuts to
 547         <option>--blob=<replaceable>FILENAME</replaceable>=<replaceable>PATH</replaceable></option>
 548         for the known filenames defined in
 549         <ulink url="https://systemd.io/USER_RECORD_BLOB_DIRS">User Record Blob Directories</ulink>.</para>
 550
 551         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
 552       </varlistentry>
 553
 554       <varlistentry>
 555         <term><option>--locked=<replaceable>BOOLEAN</replaceable></option></term>
 556
 557         <listitem><para>Takes a boolean argument. Specifies whether this user account shall be locked. If
 558         true logins into this account are prohibited, if false (the default) they are permitted (of course,
 559         only if authorization otherwise succeeds).</para>
 560
 561         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 562       </varlistentry>
 563
 564       <varlistentry>
 565         <term><option>--not-before=<replaceable>TIMESTAMP</replaceable></option></term>
 566         <term><option>--not-after=<replaceable>TIMESTAMP</replaceable></option></term>
 567
 568         <listitem><para>These options take a timestamp string, in the format documented in
 569         <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry> and
 570         configures points in time before and after logins into this account are not
 571         permitted.</para>
 572
 573         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 574       </varlistentry>
 575
 576       <varlistentry>
 577         <term><option>--rate-limit-interval=<replaceable>SECS</replaceable></option></term>
 578         <term><option>--rate-limit-burst=<replaceable>NUMBER</replaceable></option></term>
 579
 580         <listitem><para>Configures a rate limit on authentication attempts for this user. If the user
 581         attempts to authenticate more often than the specified number, on a specific system, within the
 582         specified time interval authentication is refused until the time interval passes. Defaults to 10
 583         times per 1min.</para>
 584
 585         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 586       </varlistentry>
 587
 588       <varlistentry>
 589         <term><option>--password-hint=<replaceable>TEXT</replaceable></option></term>
 590
 591         <listitem><para>Takes a password hint to store alongside the user record. This string is stored
 592         accessible only to privileged users and the user itself and may not be queried by other users.
 593         Example: <option>--password-hint="My first pet's name"</option>.</para>
 594
 595         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 596       </varlistentry>
 597
 598       <varlistentry>
 599         <term><option>--enforce-password-policy=<replaceable>BOOL</replaceable></option></term>
 600         <term><option>-P</option></term>
 601
 602         <listitem><para>Takes a boolean argument. Configures whether to enforce the system's password policy
 603         for this user, regarding quality and strength of selected passwords. Defaults to
 604         on. <option>-P</option> is short for
 605         <option>---enforce-password-policy=no</option>.</para>
 606
 607         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 608       </varlistentry>
 609
 610       <varlistentry>
 611         <term><option>--password-change-now=<replaceable>BOOL</replaceable></option></term>
 612
 613         <listitem><para>Takes a boolean argument. If true the user is asked to change their password on next
 614         login.</para>
 615
 616         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 617       </varlistentry>
 618
 619       <varlistentry>
 620         <term><option>--password-change-min=<replaceable>TIME</replaceable></option></term>
 621         <term><option>--password-change-max=<replaceable>TIME</replaceable></option></term>
 622         <term><option>--password-change-warn=<replaceable>TIME</replaceable></option></term>
 623         <term><option>--password-change-inactive=<replaceable>TIME</replaceable></option></term>
 624
 625         <listitem><para>Each of these options takes a time span specification as argument (in the syntax
 626         documented in
 627         <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>) and
 628         configures various aspects of the user's password expiration policy. Specifically,
 629         <option>--password-change-min=</option> configures how much time has to pass after changing the
 630         password of the user until the password may be changed again. If the user tries to change their
 631         password before this time passes the attempt is refused. <option>--password-change-max=</option>
 632         configures how soon after it has been changed the password expires and needs to be changed again.
 633         After this time passes logging in may only proceed after the password is changed.
 634         <option>--password-change-warn=</option> specifies how much earlier than then the time configured
 635         with <option>--password-change-max=</option> the user is warned at login to change their password as
 636         it will expire soon. Finally <option>--password-change-inactive=</option> configures the time which
 637         has to pass after the password as expired until the user is not permitted to log in or change the
 638         password anymore. Note that these options only apply to password authentication, and do not apply to
 639         other forms of authentication, for example PKCS#11-based security token
 640         authentication.</para>
 641
 642         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 643       </varlistentry>
 644
 645       <varlistentry>
 646         <term><option>--disk-size=<replaceable>BYTES</replaceable></option></term>
 647         <listitem><para>Either takes a size in bytes as argument (possibly using the usual K, M, G, …
 648         suffixes for 1024 base values), a percentage value, or the special strings <literal>min</literal> or
 649         <literal>max</literal>, and configures the disk space to assign to the user. If a percentage value is
 650         specified (i.e. the argument suffixed with <literal>%</literal>) it is taken relative to the
 651         available disk space of the backing file system. If specified as <literal>min</literal> assigns the
 652         minimal disk space permitted by the constraints of the backing file system and other limits, when
 653         specified as <literal>max</literal> assigns the maximum disk space available. If the LUKS2 backend is
 654         used this configures the size of the loopback file and file system contained therein. For the other
 655         storage backends configures disk quota using the filesystem's native quota logic, if available. If
 656         not specified, defaults to 85% of the available disk space for the LUKS2 backend and to no quota for
 657         the others.</para>
 658
 659         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 660       </varlistentry>
 661
 662       <varlistentry>
 663         <term><option>--access-mode=<replaceable>MODE</replaceable></option></term>
 664
 665         <listitem><para>Takes a UNIX file access mode written in octal. Configures the access mode of the
 666         home directory itself. Note that this is only used when the directory is first created, and the user
 667         may change this any time afterwards. Example:
 668         <option>--access-mode=0700</option></para>
 669
 670         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 671       </varlistentry>
 672
 673       <varlistentry>
 674         <term><option>--umask=<replaceable>MASK</replaceable></option></term>
 675
 676         <listitem><para>Takes the access mode mask (in octal syntax) to apply to newly created files and
 677         directories of the user ("umask"). If set this controls the initial umask set for all login sessions of
 678         the user, possibly overriding the system's defaults.</para>
 679
 680         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 681       </varlistentry>
 682
 683       <varlistentry>
 684         <term><option>--nice=<replaceable>NICE</replaceable></option></term>
 685
 686         <listitem><para>Takes the numeric scheduling priority ("nice level") to apply to the processes of the user at login
 687         time. Takes a numeric value in the range -20 (highest priority) to 19 (lowest priority).</para>
 688
 689         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 690       </varlistentry>
 691
 692       <varlistentry>
 693         <term><option>--rlimit=<replaceable>LIMIT</replaceable>=<replaceable>VALUE</replaceable><optional>:<replaceable>VALUE</replaceable></optional></option></term>
 694
 695         <listitem><para>Allows configuration of resource limits for processes of this user, see <citerefentry
 696         project='man-pages'><refentrytitle>getrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 697         for details. Takes a resource limit name (e.g. <literal>LIMIT_NOFILE</literal>) followed by an equal
 698         sign, followed by a numeric limit. Optionally, separated by colon a second numeric limit may be
 699         specified. If two are specified this refers to the soft and hard limits, respectively. If only one
 700         limit is specified the setting sets both limits in one.</para>
 701
 702         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 703       </varlistentry>
 704
 705       <varlistentry>
 706         <term><option>--tasks-max=<replaceable>TASKS</replaceable></option></term>
 707
 708         <listitem><para>Takes a non-zero unsigned integer as argument. Configures the maximum number of tasks
 709         (i.e. threads, where each process is at least one thread) the user may have at any given time. This
 710         limit applies to all tasks forked off the user's sessions, even if they change user identity via
 711         <citerefentry project='man-pages'><refentrytitle>su</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 712         or a similar tool. Use <option>--rlimit=LIMIT_NPROC=</option> to place a limit on the tasks actually
 713         running under the UID of the user, thus excluding any child processes that might have changed user
 714         identity. This controls the <varname>TasksMax=</varname> setting of the per-user systemd slice unit
 715         <filename>user-$UID.slice</filename>. See
 716         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 717         for further details.</para>
 718
 719         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 720       </varlistentry>
 721
 722       <varlistentry>
 723         <term><option>--memory-high=<replaceable>BYTES</replaceable></option></term>
 724         <term><option>--memory-max=<replaceable>BYTES</replaceable></option></term>
 725
 726         <listitem><para>Set a limit on the memory a user may take up on a system at any given time in bytes
 727         (the usual K, M, G, … suffixes are supported, to the base of 1024). This includes all memory used by
 728         the user itself and all processes they forked off that changed user credentials. This controls the
 729         <varname>MemoryHigh=</varname> and <varname>MemoryMax=</varname> settings of the per-user systemd
 730         slice unit <filename>user-$UID.slice</filename>. See
 731         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 732         for further details.</para>
 733
 734         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 735       </varlistentry>
 736
 737       <varlistentry>
 738         <term><option>--cpu-weight=<replaceable>WEIGHT</replaceable></option></term>
 739         <term><option>--io-weight=<replaceable>WEIGHT</replaceable></option></term>
 740
 741         <listitem><para>Set CPU and IO scheduling weights of the processes of the user, including those of
 742         processes forked off by the user that changed user credentials. Takes a numeric value in the range
 743         1…10000. This controls the <varname>CPUWeight=</varname> and <varname>IOWeight=</varname> settings of
 744         the per-user systemd slice unit <filename>user-$UID.slice</filename>. See
 745         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 746         for further details.</para>
 747
 748         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 749       </varlistentry>
 750
 751       <varlistentry>
 752         <term><option>--storage=<replaceable>STORAGE</replaceable></option></term>
 753
 754         <listitem><para>Selects the storage mechanism to use for this home directory. Takes one of
 755         <literal>luks</literal>, <literal>fscrypt</literal>, <literal>directory</literal>,
 756         <literal>subvolume</literal>, <literal>cifs</literal>. For details about these mechanisms, see
 757         above. If a new home directory is created and the storage type is not specifically specified,
 758         <citerefentry><refentrytitle>homed.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 759         defines which default storage to use.</para>
 760
 761         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 762       </varlistentry>
 763
 764       <varlistentry>
 765         <term><option>--image-path=<replaceable>PATH</replaceable></option></term>
 766
 767         <listitem><para>Takes a file system path. Configures where to place the user's home directory. When
 768         LUKS2 storage is used refers to the path to the loopback file, otherwise to the path to the home
 769         directory (which may be in <filename>/home/</filename> or any other accessible filesystem). When
 770         unspecified defaults to <filename>/home/$USER.home</filename> when LUKS storage is used and
 771         <filename>/home/$USER.homedir</filename> for the other storage mechanisms. Not defined for the
 772         <literal>cifs</literal> storage mechanism. To use LUKS2 storage on a regular block device (for
 773         example a USB stick) pass the path to the block device here. Specifying the path to a directory here
 774         when using LUKS2 storage is not allowed. Similar, specifying the path to a regular file or device
 775         node is not allowed if any of the other storage backends are used.</para>
 776
 777         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 778       </varlistentry>
 779
 780       <varlistentry>
 781         <term><option>--drop-caches=<replaceable>BOOL</replaceable></option></term>
 782
 783         <listitem><para>Automatically flush OS file system caches on logout. This is useful in combination
 784         with the fscrypt storage backend to ensure the OS does not keep decrypted versions of the files and
 785         directories in memory (and accessible) after logout. This option is also supported on other backends,
 786         but should not bring any benefit there. Defaults to off, except if the selected storage backend is
 787         fscrypt, where it defaults to on. Note that flushing OS caches will negatively influence performance
 788         of the OS shortly after logout.</para>
 789
 790         <xi:include href="version-info.xml" xpointer="v250"/></listitem>
 791       </varlistentry>
 792
 793       <varlistentry>
 794         <term><option>--fs-type=<replaceable>TYPE</replaceable></option></term>
 795
 796         <listitem><para>When LUKS2 storage is used configures the file system type to use inside the home
 797         directory LUKS2 container. One of <literal>btrfs</literal>, <literal>ext4</literal>,
 798         <literal>xfs</literal>. If not specified
 799         <citerefentry><refentrytitle>homed.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 800         defines which default file system type to use. Note that <literal>xfs</literal> is not recommended as
 801         its support for file system resizing is too limited.</para>
 802
 803         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 804       </varlistentry>
 805
 806       <varlistentry>
 807         <term><option>--luks-discard=<replaceable>BOOL</replaceable></option></term>
 808
 809         <listitem><para>When LUKS2 storage is used configures whether to enable the
 810         <literal>discard</literal> feature of the file system. If enabled the file system on top of the LUKS2
 811         volume will report empty block information to LUKS2 and the loopback file below, ensuring that empty
 812         space in the home directory is returned to the backing file system below the LUKS2 volume, resulting
 813         in a "sparse" loopback file. This option mostly defaults to off, since this permits over-committing
 814         home directories which results in I/O errors if the underlying file system runs full while the upper
 815         file system wants to allocate a block. Such I/O errors are generally not handled well by file systems
 816         nor applications. When LUKS2 storage is used on top of regular block devices (instead of on top a
 817         loopback file) the discard logic defaults to on.</para>
 818
 819         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 820       </varlistentry>
 821
 822       <varlistentry>
 823         <term><option>--luks-offline-discard=<replaceable>BOOL</replaceable></option></term>
 824
 825         <listitem><para>Similar to <option>--luks-discard=</option>, controls the trimming of the file
 826         system. However, while <option>--luks-discard=</option> controls what happens when the home directory
 827         is active, <option>--luks-offline-discard=</option> controls what happens when it becomes inactive,
 828         i.e. whether to trim/allocate the storage when deactivating the home directory. This option defaults
 829         to on, to ensure disk space is minimized while a user is not logged in.</para>
 830
 831         <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 832       </varlistentry>
 833
 834       <varlistentry>
 835         <term><option>--luks-extra-mount-options=<replaceable>OPTIONS</replaceable></option></term>
 836
 837         <listitem><para>Takes a string containing additional mount options to use when mounting the LUKS
 838         volume. If specified, this string will be appended to the default, built-in mount
 839         options.</para>
 840
 841         <xi:include href="version-info.xml" xpointer="v250"/></listitem>
 842       </varlistentry>
 843
 844       <varlistentry>
 845         <term><option>--luks-cipher=<replaceable>CIPHER</replaceable></option></term>
 846         <term><option>--luks-cipher-mode=<replaceable>MODE</replaceable></option></term>
 847         <term><option>--luks-volume-key-size=<replaceable>BYTES</replaceable></option></term>
 848         <term><option>--luks-pbkdf-type=<replaceable>TYPE</replaceable></option></term>
 849         <term><option>--luks-pbkdf-hash-algorithm=<replaceable>ALGORITHM</replaceable></option></term>
 850         <term><option>--luks-pbkdf-force-iterations=<replaceable>ITERATIONS</replaceable></option></term>
 851         <term><option>--luks-pbkdf-time-cost=<replaceable>SECONDS</replaceable></option></term>
 852         <term><option>--luks-pbkdf-memory-cost=<replaceable>BYTES</replaceable></option></term>
 853         <term><option>--luks-pbkdf-parallel-threads=<replaceable>THREADS</replaceable></option></term>
 854         <term><option>--luks-sector-size=<replaceable>BYTES</replaceable></option></term>
 855
 856         <listitem><para>Configures various cryptographic parameters for the LUKS2 storage mechanism. See
 857         <citerefentry
 858         project='man-pages'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 859         for details on the specific attributes.</para>
 860
 861         <para>Note that <command>homectl</command> uses bytes for key size, like
 862         <filename>/proc/crypto</filename>, but <citerefentry
 863         project='man-pages'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 864         uses bits.</para>
 865
 866         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 867       </varlistentry>
 868
 869       <varlistentry>
 870         <term><option>--auto-resize-mode=</option></term>
 871
 872         <listitem><para>Configures whether to automatically grow and/or shrink the backing file system on
 873         login and logout. Takes one of the strings <literal>off</literal>, <literal>grow</literal>,
 874         <literal>shrink-and-grow</literal>. Only applies to the LUKS2 backend currently, and if the btrfs
 875         file system is used inside it (since only then online growing/shrinking of the file system is
 876         supported). Defaults to <literal>shrink-and-grow</literal>, if LUKS2/btrfs is used, otherwise is
 877         off. If set to <literal>off</literal> no automatic shrinking/growing during login or logout is
 878         done. If set to <literal>grow</literal> the home area is grown to the size configured via
 879         <option>--disk-size=</option> should it currently be smaller. If it already matches the configured
 880         size or is larger no operation is executed. If set to <literal>shrink-and-grow</literal> the home
 881         area is also resized during logout to the minimal size the used disk space and file system
 882         constraints permit. This mode thus ensures that while a home area is activated it is sized to the
 883         configured size, but while deactivated it is compacted taking up only the minimal space possible.
 884         Note that if the system is powered off abnormally or if the user otherwise not logged out cleanly the
 885         shrinking operation will not take place, and the user has to re-login/logout again before it is
 886         executed again.</para>
 887
 888         <xi:include href="version-info.xml" xpointer="v250"/></listitem>
 889       </varlistentry>
 890
 891       <varlistentry>
 892         <term><option>--rebalance-weight=</option></term>
 893
 894         <listitem><para>Configures the weight parameter for the free disk space rebalancing logic. Only
 895         applies to the LUKS2 backend (since for the LUKS2 backend disk space is allocated from a per-user
 896         loopback file system instead of immediately from a common pool like the other backends do it). In
 897         regular intervals free disk space in the active home areas and their backing storage is redistributed
 898         among them, taking the weight value configured here into account. Expects an integer in the range
 899         1…10000, or the special string <literal>off</literal>. If not specified defaults to 100. The weight
 900         is used to scale free space made available to the home areas: a home area with a weight of 200 will
 901         get twice the free space as one with a weight of 100; a home area with a weight of 50 will get half
 902         of that. The backing file system will be assigned space for a weight of 20. If set to
 903         <literal>off</literal> no automatic free space distribution is done for this home area. Note that
 904         resizing the home area explicitly (with <command>homectl resize</command> see below) will implicitly
 905         turn off the automatic rebalancing. To reenable the automatic rebalancing use
 906         <option>--rebalance-weight=</option> with an empty parameter.</para>
 907
 908         <xi:include href="version-info.xml" xpointer="v250"/></listitem>
 909       </varlistentry>
 910
 911       <varlistentry>
 912         <term><option>--nosuid=<replaceable>BOOL</replaceable></option></term>
 913         <term><option>--nodev=<replaceable>BOOL</replaceable></option></term>
 914         <term><option>--noexec=<replaceable>BOOL</replaceable></option></term>
 915
 916         <listitem><para>Configures the <literal>nosuid</literal>, <literal>nodev</literal> and
 917         <literal>noexec</literal> mount options for the home directories. By default <literal>nodev</literal>
 918         and <literal>nosuid</literal> are on, while <literal>noexec</literal> is off. For details about these
 919         mount options see <citerefentry
 920         project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 921
 922         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 923       </varlistentry>
 924
 925       <varlistentry>
 926         <term><option>--cifs-domain=<replaceable>DOMAIN</replaceable></option></term>
 927         <term><option>--cifs-user-name=<replaceable>USER</replaceable></option></term>
 928         <term><option>--cifs-service=<replaceable>SERVICE</replaceable></option></term>
 929         <term><option>--cifs-extra-mount-options=<replaceable>OPTIONS</replaceable></option></term>
 930
 931         <listitem><para>Configures the Windows File Sharing (CIFS) domain and user to associate with the home
 932         directory/user account, as well as the file share ("service") to mount as directory. The latter is
 933         used when <literal>cifs</literal> storage is selected. The file share should be specified in format
 934         <literal>//<replaceable>host</replaceable>/<replaceable>share</replaceable>/<replaceable>directory/…</replaceable></literal>. The
 935         directory part is optional — if not specified the home directory will be placed in the top-level
 936         directory of the share. The <option>--cifs-extra-mount-options=</option> setting allows specifying
 937         additional mount options when mounting the share, see <citerefentry
 938         project='man-pages'><refentrytitle>mount.cifs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 939         for details.</para>
 940
 941         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 942       </varlistentry>
 943
 944       <varlistentry>
 945         <term><option>--stop-delay=<replaceable>SECS</replaceable></option></term>
 946
 947         <listitem><para>Configures the time the per-user service manager shall continue to run after the all
 948         sessions of the user ended. The default is configured in
 949         <citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> (for
 950         home directories of LUKS2 storage located on removable media this defaults to 0 though). A longer
 951         time makes sure quick, repetitive logins are more efficient as the user's service manager doesn't
 952         have to be started every time.</para>
 953
 954         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 955       </varlistentry>
 956
 957       <varlistentry>
 958         <term><option>--kill-processes=<replaceable>BOOL</replaceable></option></term>
 959
 960         <listitem><para>Configures whether to kill all processes of the user on logout. The default is
 961         configured in
 962         <citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 963
 964         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 965       </varlistentry>
 966
 967       <varlistentry>
 968         <term><option>--auto-login=<replaceable>BOOL</replaceable></option></term>
 969
 970         <listitem><para>Takes a boolean argument. Configures whether the graphical UI of the system should
 971         automatically log this user in if possible. Defaults to off. If less or more than one user is marked
 972         this way automatic login is disabled.</para>
 973
 974         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 975       </varlistentry>
 976
 977       <varlistentry>
 978         <term><option>--session-launcher=<replaceable>LAUNCHER</replaceable></option></term>
 979
 980         <listitem><para>Takes a string argument. Configures the user's preferred session launcher
 981         .desktop entry file (i.e. <literal>gnome</literal>, <literal>plasma</literal>, or other names that
 982         appear in <filename>/usr/share/xesssions/</filename> or <filename>/usr/share/wayland-sessions</filename>).
 983         This is read by the display manager to pick the default session that is launched when the user logs in.</para>
 984
 985         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
 986       </varlistentry>
 987
 988       <varlistentry>
 989         <term><option>--session-type=<replaceable>TYPE</replaceable></option></term>
 990
 991         <listitem><para>Takes a string argument. Configures the user's preferred session type
 992         (i.e. <literal>x11</literal>, <literal>wayland</literal>, and other values accepted by
 993         <varname>$XDG_SESSION_TYPE</varname>). This is read by the display manage to pick the
 994         default session type the user is logged into.</para>
 995
 996         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
 997       </varlistentry>
 998     </variablelist>
 999   </refsect1>
1000
1001   <refsect1>
1002     <title>Commands</title>
1003
1004     <para>The following commands are understood:</para>
1005
1006     <variablelist>
1007
1008       <varlistentry>
1009         <term><command>list</command></term>
1010
1011         <listitem><para>List all home directories (along with brief details) currently managed by
1012         <filename>systemd-homed.service</filename>. This command is also executed if none is specified on the
1013         command line. (Note that the list of users shown by this command does not include users managed by
1014         other subsystems, such as system users or any traditional users listed in
1015         <filename>/etc/passwd</filename>.)</para>
1016
1017         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1018       </varlistentry>
1019
1020       <varlistentry>
1021         <term><command>activate</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
1022
1023         <listitem><para>Activate one or more home directories. The home directories of each listed user will
1024         be activated and made available under their mount points (typically in
1025         <filename>/home/$USER</filename>). Note that any home activated this way stays active indefinitely,
1026         until it is explicitly deactivated again (with <command>deactivate</command>, see below), or the user
1027         logs in and out again and it thus is deactivated due to the automatic deactivation-on-logout
1028         logic.</para>
1029
1030         <para>Activation of a home directory involves various operations that depend on the selected storage
1031         mechanism. If the LUKS2 mechanism is used, this generally involves: inquiring the user for a
1032         password, setting up a loopback device, validating and activating the LUKS2 volume, checking the file
1033         system, mounting the file system, and potentially changing the ownership of all included files to the
1034         correct UID/GID.</para>
1035
1036         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1037       </varlistentry>
1038
1039       <varlistentry>
1040         <term><command>deactivate</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
1041
1042         <listitem><para>Deactivate one or more home directories. This undoes the effect of
1043         <command>activate</command>.</para>
1044
1045         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1046       </varlistentry>
1047
1048       <varlistentry>
1049         <term><command>inspect</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
1050
1051         <listitem><para>Show various details about the specified home directories. This shows various
1052         information about the home directory and its user account, including runtime data such as current
1053         state, disk use and similar. Combine with <option>--json=</option> to show the detailed JSON user
1054         record instead, possibly combined with <option>--export-format=</option> to suppress certain aspects
1055         of the output.</para>
1056
1057         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1058       </varlistentry>
1059
1060       <varlistentry>
1061         <term><command>authenticate</command> <replaceable>USER</replaceable> [<replaceable>USER…</replaceable>]</term>
1062
1063         <listitem><para>Validate authentication credentials of a home directory. This queries the caller for
1064         a password (or similar) and checks that it correctly unlocks the home directory. This leaves the home
1065         directory in the state it is in, i.e. it leaves the home directory in inactive state if it was
1066         inactive before, and in active state if it was active before.</para>
1067
1068         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1069       </varlistentry>
1070
1071       <varlistentry>
1072         <term><command>create</command> <replaceable>USER</replaceable></term>
1073         <term><command>create</command> <option>--identity=<replaceable>PATH</replaceable></option> <optional><replaceable>USER</replaceable></optional></term>
1074
1075         <listitem><para>Create a new home directory/user account of the specified name. Use the various
1076         user record property options (as documented above) to control various aspects of the home directory
1077         and its user accounts.</para>
1078
1079         <para>The specified user name should follow the strict syntax described on <ulink
1080         url="https://systemd.io/USER_NAMES">User/Group Name Syntax</ulink>.</para>
1081
1082         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1083       </varlistentry>
1084
1085       <varlistentry>
1086         <term><command>remove</command> <replaceable>USER</replaceable></term>
1087
1088         <listitem><para>Remove a home directory/user account. This will remove both the home directory's user
1089         record and the home directory itself, and thus delete all files and directories owned by the
1090         user.</para>
1091
1092         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1093       </varlistentry>
1094
1095       <varlistentry>
1096         <term><command>update</command> <replaceable>USER</replaceable></term>
1097         <term><command>update</command> <option>--identity=<replaceable>PATH</replaceable></option> <optional><replaceable>USER</replaceable></optional></term>
1098
1099         <listitem><para>Update a home directory/user account. Use the various user record property options
1100         (as documented above) to make changes to the account, or alternatively provide a full, updated JSON
1101         user record via the <option>--identity=</option> option.</para>
1102
1103         <para>Note that changes to user records not signed by a cryptographic private key available locally
1104         are not permitted, unless <option>--identity=</option> is used with a user record that is already
1105         correctly signed by a recognized private key.</para>
1106
1107         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1108       </varlistentry>
1109
1110       <varlistentry>
1111         <term><command>passwd</command> <replaceable>USER</replaceable></term>
1112
1113         <listitem><para>Change the password of the specified home directory/user account.</para>
1114
1115         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1116       </varlistentry>
1117
1118       <varlistentry>
1119         <term><command>resize</command> <replaceable>USER</replaceable> <replaceable>BYTES</replaceable></term>
1120
1121         <listitem><para>Change the disk space assigned to the specified home directory. If the LUKS2 storage
1122         mechanism is used this will automatically resize the loopback file and the file system contained
1123         within. Note that if <literal>ext4</literal> is used inside of the LUKS2 volume, it is necessary to
1124         deactivate the home directory before shrinking it (i.e the user has to log out). Growing can be done
1125         while the home directory is active. If <literal>xfs</literal> is used inside of the LUKS2 volume the
1126         home directory may not be shrunk whatsoever. On all three of <literal>ext4</literal>,
1127         <literal>xfs</literal> and <literal>btrfs</literal> the home directory may be grown while the user is
1128         logged in, and on the latter also shrunk while the user is logged in. If the
1129         <literal>subvolume</literal>, <literal>directory</literal>, <literal>fscrypt</literal> storage
1130         mechanisms are used, resizing will change file system quota. The size parameter may make use of the
1131         usual suffixes B, K, M, G, T (to the base of 1024). The special strings <literal>min</literal> and
1132         <literal>max</literal> may be specified in place of a numeric size value, for minimizing or
1133         maximizing disk space assigned to the home area, taking constraints of the file system, disk usage inside
1134         the home area and on the backing storage into account.</para>
1135
1136         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1137       </varlistentry>
1138
1139       <varlistentry>
1140         <term><command>lock</command> <replaceable>USER</replaceable></term>
1141
1142         <listitem><para>Temporarily suspend access to the user's home directory and remove any associated
1143         cryptographic keys from memory. Any attempts to access the user's home directory will stall until the
1144         home directory is unlocked again (i.e. re-authenticated). This functionality is primarily intended to
1145         be used during system suspend to make sure the user's data cannot be accessed until the user
1146         re-authenticates on resume. This operation is only defined for home directories that use the LUKS2
1147         storage mechanism.</para>
1148
1149         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1150       </varlistentry>
1151
1152       <varlistentry>
1153         <term><command>unlock</command> <replaceable>USER</replaceable></term>
1154
1155         <listitem><para>Resume access to the user's home directory again, undoing the effect of
1156         <command>lock</command> above. This requires authentication of the user, as the cryptographic keys
1157         required for access to the home directory need to be reacquired.</para>
1158
1159         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1160       </varlistentry>
1161
1162       <varlistentry>
1163         <term><command>lock-all</command></term>
1164
1165         <listitem><para>Execute the <command>lock</command> command on all suitable home directories at
1166         once. This operation is generally executed on system suspend (i.e. by <command>systemctl
1167         suspend</command> and related commands), to ensure all active user's cryptographic keys for accessing
1168         their home directories are removed from memory.</para>
1169
1170         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1171       </varlistentry>
1172
1173       <varlistentry>
1174         <term><command>deactivate-all</command></term>
1175
1176         <listitem><para>Execute the <command>deactivate</command> command on all active home directories at
1177         once. This operation is generally executed on system shut down (i.e. by <command>systemctl
1178         poweroff</command> and related commands), to ensure all active user's home directories are fully
1179         deactivated before <filename>/home/</filename> and related file systems are unmounted.</para>
1180
1181         <xi:include href="version-info.xml" xpointer="v247"/></listitem>
1182       </varlistentry>
1183
1184       <varlistentry>
1185         <term><command>with</command> <replaceable>USER</replaceable> <replaceable>COMMAND…</replaceable></term>
1186
1187         <listitem><para>Activate the specified user's home directory, run the specified command (under the
1188         caller's identity, not the specified user's) and deactivate the home directory afterwards again
1189         (unless the user is logged in otherwise). This command is useful for running privileged backup
1190         scripts and such, but requires authentication with the user's credentials in order to be able to
1191         unlock the user's home directory.</para>
1192
1193         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
1194       </varlistentry>
1195
1196       <varlistentry>
1197         <term><command>rebalance</command></term>
1198
1199         <listitem><para>Rebalance free disk space between active home areas and the backing storage. See
1200         <option>--rebalance-weight=</option> above. This executes no operation unless there's at least one
1201         active LUKS2 home area that has disk space rebalancing enabled. This operation is synchronous: it
1202         will only complete once disk space is rebalanced according to the rebalancing weights. Note that
1203         rebalancing also takes place automatically in the background in regular intervals. Use this command
1204         to synchronously ensure disk space is properly redistributed before initiating an operation requiring
1205         large amounts of disk space.</para>
1206
1207         <xi:include href="version-info.xml" xpointer="v250"/></listitem>
1208       </varlistentry>
1209
1210       <varlistentry>
1211         <term><command>firstboot</command></term>
1212
1213         <listitem><para>This command is supposed to be invoked during the initial boot of the system. It
1214         checks whether any regular home area exists so far, and if not queries the user interactively on the
1215         console for user name and password and creates one. Alternatively, if one or more service credentials
1216         whose name starts with <literal>home.create.</literal> are passed to the command (containing a user
1217         record in JSON format) these users are automatically created at boot.</para>
1218
1219         <para>This command is invoked by the <filename>systemd-homed-firstboot.service</filename> service
1220         unit.</para>
1221
1222         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
1223       </varlistentry>
1224     </variablelist>
1225   </refsect1>
1226
1227   <refsect1>
1228     <title>Credentials</title>
1229
1230     <para>When invoked with the <command>firstboot</command> command, <command>homectl</command> supports the
1231     service credentials logic as implemented by
1232     <varname>ImportCredential=</varname>/<varname>LoadCredential=</varname>/<varname>SetCredential=</varname>
1233     (see <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
1234     details). The following credentials are used when passed in:</para>
1235
1236     <variablelist class='system-credentials'>
1237       <varlistentry>
1238         <term><varname>home.create.*</varname></term>
1239
1240         <listitem><para>If one or more credentials whose names begin with <literal>home.create.</literal>,
1241         followed by a valid UNIX username are passed, a new home area is created, one for each specified user
1242         record.</para>
1243
1244         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
1245       </varlistentry>
1246     </variablelist>
1247   </refsect1>
1248
1249   <refsect1>
1250     <title>Kernel Command Line</title>
1251
1252     <variablelist class='kernel-commandline-options'>
1253       <varlistentry>
1254         <term><varname>systemd.firstboot=</varname></term>
1255
1256         <listitem><para>This boolean will disable the effect of <command>homectl firstboot</command>
1257         command. It's primarily interpreted by
1258         <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
1259
1260         <xi:include href="version-info.xml" xpointer="v256"/></listitem>
1261       </varlistentry>
1262     </variablelist>
1263   </refsect1>
1264
1265   <refsect1>
1266     <title>Exit status</title>
1267
1268     <para>On success, 0 is returned, a non-zero failure code otherwise.</para>
1269
1270     <para>When a command is invoked with <command>with</command>, the exit status of the child is
1271     propagated. Effectively, <command>homectl</command> will exit without error if the command is
1272     successfully invoked <emphasis>and</emphasis> finishes successfully.</para>
1273   </refsect1>
1274
1275   <xi:include href="common-variables.xml" />
1276
1277   <refsect1>
1278     <title>Examples</title>
1279
1280     <example>
1281       <title>Create a user <literal>waldo</literal> in the administrator group <literal>wheel</literal>, and
1282       assign 500 MiB disk space to them.</title>
1283
1284       <programlisting>homectl create waldo --real-name="Waldo McWaldo" -G wheel --disk-size=500M</programlisting>
1285     </example>
1286
1287     <example>
1288       <title>Create a user <literal>wally</literal> on a USB stick, and assign a maximum of 500 concurrent
1289       tasks to them.</title>
1290
1291       <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>
1292     </example>
1293
1294     <example>
1295       <title>Change nice level of user <literal>odlaw</literal> to +5 and make sure the environment variable
1296       <varname>$SOME</varname> is set to the string <literal>THING</literal> for them on login.</title>
1297
1298       <programlisting>homectl update odlaw --nice=5 --setenv=SOME=THING</programlisting>
1299     </example>
1300
1301     <example>
1302       <title>Set up authentication with a YubiKey security token using PKCS#11/PIV:</title>
1303
1304       <programlisting># Clear the Yubikey from any old keys (careful!)
1305 ykman piv reset
1306
1307 # Generate a new private/public key pair on the device, store the public key in 'pubkey.pem'.
1308 ykman piv generate-key -a RSA2048 9d pubkey.pem
1309
1310 # Create a self-signed certificate from this public key, and store it on the device.
1311 ykman piv generate-certificate --subject "Knobelei" 9d pubkey.pem
1312
1313 # We don't need the public key on disk anymore
1314 rm pubkey.pem
1315
1316 # Allow the security token to unlock the account of user 'lafcadio'.
1317 homectl update lafcadio --pkcs11-token-uri=auto</programlisting>
1318     </example>
1319
1320     <example>
1321       <title>Set up authentication with a FIDO2 security token:</title>
1322
1323       <programlisting># Allow a FIDO2 security token to unlock the account of user 'nihilbaxter'.
1324 homectl update nihilbaxter --fido2-device=auto</programlisting>
1325     </example>
1326   </refsect1>
1327
1328   <refsect1>
1329     <title>See Also</title>
1330     <para><simplelist type="inline">
1331       <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
1332       <member><citerefentry><refentrytitle>systemd-homed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
1333       <member><citerefentry><refentrytitle>homed.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
1334       <member><citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
1335       <member><citerefentry project='man-pages'><refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
1336       <member><citerefentry project='man-pages'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
1337     </simplelist></para>
1338   </refsect1>
1339
1340 </refentry>