1HOMECTL(1) homectl HOMECTL(1)
2
6 homectl - Create, remove, change or inspect home directories
7
9 homectl [OPTIONS...] {COMMAND} [NAME...]
10
12 homectl may be used to create, remove, change or inspect a user's home
13 directory. It's primarily a command interfacing with systemd-
14 homed.service(8) which manages home directories of users.
15 Home directories managed by systemd-homed.service are self-contained,
17 and thus include the user's full metadata record in the home's data
18 storage itself, making them easy to migrate between machines. In
19 particular, a home directory describes a matching user record, and
20 every user record managed by systemd-homed.service also implies
21 existence and encapsulation of a home directory. The user account and
22 home directory become the same concept.
23 The following backing storage mechanisms are supported:
25 • An individual LUKS2 encrypted loopback file for a user, stored in
27 /home/*.home. At login the file system contained in this files is
28 mounted, after the LUKS2 encrypted volume has been attached. The
29 user's password is identical to the encryption passphrase of the
30 LUKS2 volume. Access to data without preceding user authentication
31 is thus not possible, even for the system administrator. This
32 storage mechanism provides the strongest data security and is thus
33 recommended.
34 • Similar, but the LUKS2 encrypted file system is located on regular
36 block device, such as an USB storage stick. In this mode home
37 directories and all data they include are nicely migratable between
38 machines, simply by plugging the USB stick into different systems
39 at different times.
40 • An encrypted directory using "fscrypt" on file systems that support
42 it (at the moment this is primarily "ext4"), located in
43 /home/*.homedir. This mechanism also provides encryption, but
44 substantially weaker than LUKS2, as most file system metadata is
45 unprotected. Moreover it currently does not support changing user
46 passwords once the home directory has been created.
47 • A "btrfs" subvolume for each user, also located in /home/*.homedir.
49 This provides no encryption, but good quota support.
50 • A regular directory for each user, also located in /home/*.homedir.
52 This provides no encryption, but is a suitable fallback available
53 on all machines, even where LUKS2, "fscrypt" or "btrfs" support is
54 not available.
55 • An individual Windows file share (CIFS) for each user.
57 Note that systemd-homed.service and homectl will not manage "classic"
59 UNIX user accounts as created with useradd(8) or similar tools. In
60 particular, this functionality is not suitable for managing system
61 users (i.e. users with a UID below 1000) but is exclusive to regular
62 ("human") users.
63 Note that users/home directories managed via systemd-homed.service do
65 not show up in /etc/passwd and similar files, they are synthesized via
66 glibc NSS during runtime. They are thus resolvable and may be
67 enumerated via the getent(1) tool.
68 This tool interfaces directly with systemd-homed.service, and may
70 execute specific commands on the home directories it manages. Since
71 every home directory managed that way also defines a JSON user and
72 group record these home directories may also be inspected and
73 enumerated via userdbctl(1).
74 Home directories managed by systemd-homed.service are usually in one of
76 two states, or in a transition state between them: when "active" they
77 are unlocked and mounted, and thus accessible to the system and its
78 programs; when "inactive" they are not mounted and thus not accessible.
79 Activation happens automatically at login of the user and usually can
80 only complete after a password (or other authentication token) has been
81 supplied. Deactivation happens after the user fully logged out. A home
82 directory remains active as long as the user is logged in at least
83 once, i.e. has at least one login session. When the user logs in a
84 second time simultaneously the home directory remains active. It is
85 deactivated only after the last of the user's sessions ends.
86
88 The following general options are understood (further options that
89 control the various properties of user records managed by
90 systemd-homed.service are documented further down):
91 --identity=FILE
93 Read the user's JSON record from the specified file. If passed as
94 "-" read the user record from standard input. The supplied JSON
95 object must follow the structure documented in JSON User
96 Records[1]. This option may be used in conjunction with the create
97 and update commands (see below), where it allows configuring the
98 user record in JSON as-is, instead of setting the individual user
99 record properties (see below).
100 --json=FORMAT, -j
102 Controls whether to output the user record in JSON format, if the
103 inspect command (see below) is used. Takes one of "pretty", "short"
104 or "off". If "pretty" human-friendly whitespace and newlines are
105 inserted in the output to make the JSON data more readable. If
106 "short" all superfluous whitespace is suppressed. If "off" (the
107 default) the user information is not shown in JSON format but in a
108 friendly human readable formatting instead. The -j option picks
109 "pretty" when run interactively and "short" otherwise.
110 --export-format=FORMAT, -E, -EE
112 When used with the inspect verb in JSON mode (see above) may be
113 used to suppress certain aspects of the JSON user record on output.
114 Specifically, if "stripped" format is used the binding and runtime
115 fields of the record are removed. If "minimal" format is used the
116 cryptographic signature is removed too. If "full" format is used
117 the full JSON record is shown (this is the default). This option is
118 useful for copying an existing user record to a different system in
119 order to create a similar user there with the same settings.
120 Specifically: homectl inspect -EE | ssh root@othersystem homectl
121 create -i- may be used as simple command line for replicating a
122 user on another host. -E is equivalent to -j
123 --export-format=stripped, -EE to -j --export-format=minimal. Note
124 that when replicating user accounts user records acquired in
125 "stripped" mode will retain the original cryptographic signatures
126 and thus may only be modified when the private key to update them
127 is available on the destination machine. When replicating users in
128 "minimal" mode, the signature is removed during the replication and
129 thus the record will be implicitly signed with the key of the
130 destination machine and may be updated there without any private
131 key replication.
132 -H, --host=
134 Execute the operation remotely. Specify a hostname, or a username
135 and hostname separated by "@", to connect to. The hostname may
136 optionally be suffixed by a port ssh is listening on, separated by
137 ":", and then a container name, separated by "/", which connects
138 directly to a specific container on the specified host. This will
139 use SSH to talk to the remote machine manager instance. Container
140 names may be enumerated with machinectl -H HOST. Put IPv6 addresses
141 in brackets.
142 -M, --machine=
144 Execute operation on a local container. Specify a container name to
145 connect to, optionally prefixed by a user name to connect as and a
146 separating "@" character. If the special string ".host" is used in
147 place of the container name, a connection to the local system is
148 made (which is useful to connect to a specific user's user bus:
149 "--user --machine=lennart@.host"). If the "@" syntax is not used,
150 the connection is made as root user. If the "@" syntax is used
151 either the left hand side or the right hand side may be omitted
152 (but not both) in which case the local user name and ".host" are
153 implied.
154 --no-pager
156 Do not pipe output into a pager.
157 --no-legend
159 Do not print the legend, i.e. column headers and the footer with
160 hints.
161 --no-ask-password
163 Do not query the user for authentication for privileged operations.
164 -h, --help
166 Print a short help text and exit.
167 --version
169 Print a short version string and exit.
170
172 The following options control various properties of the user
173 records/home directories that systemd-homed.service manages. These
174 switches may be used in conjunction with the create and update commands
175 for configuring various aspects of the home directory and the user
176 account:
177 --real-name=NAME, -c NAME
179 The real name for the user. This corresponds with the GECOS field
180 on classic UNIX NSS records.
181 --realm=REALM
183 The realm for the user. The realm associates a user with a specific
184 organization or installation, and allows distinguishing users of
185 the same name defined in different contexts. The realm can be any
186 string that also qualifies as valid DNS domain name, and it is
187 recommended to use the organization's or installation's domain name
188 for this purpose, but this is not enforced nor required. On each
189 system only a single user of the same name may exist, and if a user
190 with the same name and realm is seen it is assumed to refer to the
191 same user while a user with the same name but different realm is
192 considered a different user. Note that this means that two users
193 sharing the same name but with distinct realms are not allowed on
194 the same system. Assigning a realm to a user is optional.
195 --email-address=EMAIL
197 Takes an electronic mail address to associate with the user. On
198 log-in the $EMAIL environment variable is initialized from this
199 value.
200 --location=TEXT
202 Takes location specification for this user. This is free-form text,
203 which might or might not be usable by geo-location applications.
204 Example: --location="Berlin, Germany" or --location="Basement, Room
205 3a"
206 --icon-name=ICON
208 Takes an icon name to associate with the user, following the scheme
209 defined by the Icon Naming Specification[2].
210 --home-dir=PATH, -dPATH
212 Takes a path to use as home directory for the user. Note that this
213 is the directory the user's home directory is mounted to while the
214 user is logged in. This is not where the user's data is actually
215 stored, see --image-path= for that. If not specified defaults to
216 /home/$USER.
217 --uid=UID
219 Takes a preferred numeric UNIX UID to assign this user. If a user
220 is to be created with the specified UID and it is already taken by
221 a different user on the local system then creation of the home
222 directory is refused. Note though, if after creating the home
223 directory it is used on a different system and the configured UID
224 is taken by another user there, then systemd-homed may assign the
225 user a different UID on that system. The specified UID must be
226 outside of the system user range. It is recommended to use the
227 60001...60513 UID range for this purpose. If not specified, the UID
228 is automatically picked. If the home directory is found to be owned
229 by a different UID when logging in, the home directory and
230 everything underneath it will have its ownership changed
231 automatically before login completes.
232 Note that users managed by systemd-homed always have a matching
234 group associated with the same name as well as a GID matching the
235 UID of the user. Thus, configuring the GID separately is not
236 permitted.
237 --member-of=GROUP, -G GROUP
239 Takes a comma-separated list of auxiliary UNIX groups this user
240 shall belong to. Example: --member-of=wheel to provide the user
241 with administrator privileges. Note that systemd-homed does not
242 manage any groups besides a group matching the user in name and
243 numeric UID/GID. Thus any groups listed here must be registered
244 independently, for example with groupadd(8). Any non-existent
245 groups are ignored. This option may be used more than once, in
246 which case all specified group lists are combined. If the user is
247 currently a member of a group which is not listed, the user will be
248 removed from the group.
249 --skel=PATH
251 Takes a file system path to a directory. Specifies the skeleton
252 directory to initialize the home directory with. All files and
253 directories in the specified path are copied into any newly create
254 home directory. If not specified defaults to /etc/skel/.
255 --shell=SHELL
257 Takes a file system path. Specifies the shell binary to execute on
258 terminal logins. If not specified defaults to /bin/bash.
259 --setenv=VARIABLE[=VALUE]
261 Takes an environment variable assignment to set for all user
262 processes. May be used multiple times to set multiple environment
263 variables. When "=" and VALUE are omitted, the value of the
264 variable with the same name in the program environment will be
265 used.
266 Note that a number of other settings also result in environment
268 variables to be set for the user, including --email=, --timezone=
269 and --language=.
270 --timezone=TIMEZONE
272 Takes a time zone location name that sets the timezone for the
273 specified user. When the user logs in the $TZ environment variable
274 is initialized from this setting. Example:
275 --timezone=Europe/Amsterdam will result in the environment variable
276 "TZ=:Europe/Amsterdam". (":" is used intentionally as part of the
277 timezone specification, see tzset(3).)
278 --language=LANG
280 Takes a specifier indicating the preferred language of the user.
281 The $LANG environment variable is initialized from this value on
282 login, and thus a value suitable for this environment variable is
283 accepted here, for example --language=de_DE.UTF8.
284 --ssh-authorized-keys=KEYS
286 Either takes a SSH authorized key line to associate with the user
287 record or a "@" character followed by a path to a file to read one
288 or more such lines from. SSH keys configured this way are made
289 available to SSH to permit access to this home directory and user
290 record. This option may be used more than once to configure
291 multiple SSH keys.
292 --pkcs11-token-uri=URI
294 Takes an RFC 7512 PKCS#11 URI referencing a security token (e.g.
295 YubiKey or PIV smartcard) that shall be able to unlock the user
296 account. The security token URI should reference a security token
297 with exactly one pair of X.509 certificate and private key. A
298 random secret key is then generated, encrypted with the public key
299 of the X.509 certificate, and stored as part of the user record. At
300 login time it is decrypted with the PKCS#11 module and then used to
301 unlock the account and associated resources. See below for an
302 example how to set up authentication with a security token.
303 Instead of a valid PKCS#11 URI, the special strings "list" and
305 "auto" may be specified. If "list" is passed, a brief table of
306 suitable, currently plugged in PKCS#11 hardware tokens is shown,
307 along with their URIs. If "auto" is passed, a suitable PKCS#11
308 hardware token is automatically selected (this operation will fail
309 if there isn't exactly one suitable token discovered). The latter
310 is a useful shortcut for the most common case where a single
311 PKCS#11 hardware token is plugged in.
312 Note that many hardware security tokens implement both PKCS#11/PIV
314 and FIDO2 with the "hmac-secret" extension (for example: the
315 YubiKey 5 series), as supported with the --fido2-device= option
316 below. Both mechanisms are similarly powerful, though FIDO2 is the
317 more modern technology. PKCS#11/PIV tokens have the benefit of
318 being recognizable before authentication and hence can be used for
319 implying the user identity to use for logging in, which FIDO2 does
320 not allow. PKCS#11/PIV devices generally require initialization
321 (i.e. storing a private/public key pair on them, see example below)
322 before they can be used; FIDO2 security tokens generally do not
323 required that, and work out of the box.
324 --fido2-credential-algorithm=STRING
326 Specify COSE algorithm used in credential generation. The default
327 value is "es256". Supported values are "es256", "rs256" and
328 "eddsa".
329 "es256" denotes ECDSA over NIST P-256 with SHA-256. "rs256"
331 denotes 2048-bit RSA with PKCS#1.5 padding and SHA-256. "eddsa"
332 denotes EDDSA over Curve25519 with SHA-512.
333 Note that your authenticator may not support some algorithms.
335 --fido2-device=PATH
337 Takes a path to a Linux "hidraw" device (e.g. /dev/hidraw1),
338 referring to a FIDO2 security token implementing the "hmac-secret"
339 extension that shall be able to unlock the user account. A random
340 salt value is generated on the host and passed to the FIDO2 device,
341 which calculates a HMAC hash of the salt using an internal secret
342 key. The result is then used as the key to unlock the user account.
343 The random salt is included in the user record, so that whenever
344 authentication is needed it can be passed to the FIDO2 token again.
345 Instead of a valid path to a FIDO2 "hidraw" device the special
347 strings "list" and "auto" may be specified. If "list" is passed, a
348 brief table of suitable discovered FIDO2 devices is shown. If
349 "auto" is passed, a suitable FIDO2 token is automatically selected,
350 if exactly one is discovered. The latter is a useful shortcut for
351 the most common case where a single FIDO2 hardware token is plugged
352 in.
353 Note that FIDO2 devices suitable for this option must implement the
355 "hmac-secret" extension. Most current devices (such as the YubiKey
356 5 series) do. If the extension is not implemented the device cannot
357 be used for unlocking home directories.
358 The FIDO2 device may be subsequently removed by setting the device
360 path to an empty string (e.g. homectl update $USER
361 --fido2-device="").
362 Note that many hardware security tokens implement both FIDO2 and
364 PKCS#11/PIV (and thus may be used with either --fido2-device= or
365 --pkcs11-token-uri=), for a discussion see above.
366 --fido2-with-client-pin=BOOL
368 When enrolling a FIDO2 security token, controls whether to require
369 the user to enter a PIN when unlocking the account (the FIDO2
370 "clientPin" feature). Defaults to "yes". (Note: this setting is
371 without effect if the security token does not support the
372 "clientPin" feature at all, or does not allow enabling or disabling
373 it.)
374 --fido2-with-user-presence=BOOL
376 When enrolling a FIDO2 security token, controls whether to require
377 the user to verify presence (tap the token, the FIDO2 "up" feature)
378 when unlocking the account. Defaults to "yes". (Note: this setting
379 is without effect if the security token does not support the "up"
380 feature at all, or does not allow enabling or disabling it.)
381 --fido2-with-user-verification=BOOL
383 When enrolling a FIDO2 security token, controls whether to require
384 user verification when unlocking the account (the FIDO2 "uv"
385 feature). Defaults to "no". (Note: this setting is without effect
386 if the security token does not support the "uv" feature at all, or
387 does not allow enabling or disabling it.)
388 --recovery-key=BOOL
390 Accepts a boolean argument. If enabled a recovery key is configured
391 for the account. A recovery key is a computer generated access key
392 that may be used to regain access to an account if the password has
393 been forgotten or the authentication token lost. The key is
394 generated and shown on screen, and should be printed or otherwise
395 transferred to a secure location. A recovery key may be entered
396 instead of a regular password to unlock the account.
397 --locked=BOOLEAN
399 Takes a boolean argument. Specifies whether this user account shall
400 be locked. If true logins into this account are prohibited, if
401 false (the default) they are permitted (of course, only if
402 authorization otherwise succeeds).
403 --not-before=TIMESTAMP, --not-after=TIMESTAMP
405 These options take a timestamp string, in the format documented in
406 systemd.time(7) and configures points in time before and after
407 logins into this account are not permitted.
408 --rate-limit-interval=SECS, --rate-limit-burst=NUMBER
410 Configures a rate limit on authentication attempts for this user.
411 If the user attempts to authenticate more often than the specified
412 number, on a specific system, within the specified time interval
413 authentication is refused until the time interval passes. Defaults
414 to 10 times per 1min.
415 --password-hint=TEXT
417 Takes a password hint to store alongside the user record. This
418 string is stored accessible only to privileged users and the user
419 itself and may not be queried by other users. Example:
420 --password-hint="My first pet's name".
421 --enforce-password-policy=BOOL, -P
423 Takes a boolean argument. Configures whether to enforce the
424 system's password policy for this user, regarding quality and
425 strength of selected passwords. Defaults to on. -P is short for
426 ---enforce-password-policy=no.
427 --password-change-now=BOOL
429 Takes a boolean argument. If true the user is asked to change their
430 password on next login.
431 --password-change-min=TIME, --password-change-max=TIME,
433 --password-change-warn=TIME, --password-change-inactive=TIME
434 Each of these options takes a time span specification as argument
435 (in the syntax documented in systemd.time(7)) and configures
436 various aspects of the user's password expiration policy.
437 Specifically, --password-change-min= configures how much time has
438 to pass after changing the password of the user until the password
439 may be changed again. If the user tries to change their password
440 before this time passes the attempt is refused.
441 --password-change-max= configures how soon after it has been
442 changed the password expires and needs to be changed again. After
443 this time passes logging in may only proceed after the password is
444 changed. --password-change-warn= specifies how much earlier than
445 then the time configured with --password-change-max= the user is
446 warned at login to change their password as it will expire soon.
447 Finally --password-change-inactive= configures the time which has
448 to pass after the password as expired until the user is not
449 permitted to log in or change the password anymore. Note that these
450 options only apply to password authentication, and do not apply to
451 other forms of authentication, for example PKCS#11-based security
452 token authentication.
453 --disk-size=BYTES
455 Either takes a size in bytes as argument (possibly using the usual
456 K, M, G, ... suffixes for 1024 base values), a percentage value, or
457 the special strings "min" or "max", and configures the disk space
458 to assign to the user. If a percentage value is specified (i.e. the
459 argument suffixed with "%") it is taken relative to the available
460 disk space of the backing file system. If specified as "min"
461 assigns the minimal disk space permitted by the constraints of the
462 backing file system and other limits, when specified as "max"
463 assigns the maximum disk space available. If the LUKS2 backend is
464 used this configures the size of the loopback file and file system
465 contained therein. For the other storage backends configures disk
466 quota using the filesystem's native quota logic, if available. If
467 not specified, defaults to 85% of the available disk space for the
468 LUKS2 backend and to no quota for the others.
469 --access-mode=MODE
471 Takes a UNIX file access mode written in octal. Configures the
472 access mode of the home directory itself. Note that this is only
473 used when the directory is first created, and the user may change
474 this any time afterwards. Example: --access-mode=0700
475 --umask=MASK
477 Takes the access mode mask (in octal syntax) to apply to newly
478 created files and directories of the user ("umask"). If set this
479 controls the initial umask set for all login sessions of the user,
480 possibly overriding the system's defaults.
481 --nice=NICE
483 Takes the numeric scheduling priority ("nice level") to apply to
484 the processes of the user at login time. Takes a numeric value in
485 the range -20 (highest priority) to 19 (lowest priority).
486 --rlimit=LIMIT=VALUE[:VALUE]
488 Allows configuration of resource limits for processes of this user,
489 see getrlimit(2) for details. Takes a resource limit name (e.g.
490 "LIMIT_NOFILE") followed by an equal sign, followed by a numeric
491 limit. Optionally, separated by colon a second numeric limit may be
492 specified. If two are specified this refers to the soft and hard
493 limits, respectively. If only one limit is specified the setting
494 sets both limits in one.
495 --tasks-max=TASKS
497 Takes a non-zero unsigned integer as argument. Configures the
498 maximum number of tasks (i.e. threads, where each process is at
499 least one thread) the user may have at any given time. This limit
500 applies to all tasks forked off the user's sessions, even if they
501 change user identity via su(1) or a similar tool. Use
502 --rlimit=LIMIT_NPROC= to place a limit on the tasks actually
503 running under the UID of the user, thus excluding any child
504 processes that might have changed user identity. This controls the
505 TasksMax= setting of the per-user systemd slice unit
506 user-$UID.slice. See systemd.resource-control(5) for further
507 details.
508 --memory-high=BYTES, --memory-max=BYTES
510 Set a limit on the memory a user may take up on a system at any
511 given time in bytes (the usual K, M, G, ... suffixes are supported,
512 to the base of 1024). This includes all memory used by the user
513 itself and all processes they forked off that changed user
514 credentials. This controls the MemoryHigh= and MemoryMax= settings
515 of the per-user systemd slice unit user-$UID.slice. See
516 systemd.resource-control(5) for further details.
517 --cpu-weight=WEIGHT, --io-weight=WEIGHT
519 Set CPU and IO scheduling weights of the processes of the user,
520 including those of processes forked off by the user that changed
521 user credentials. Takes a numeric value in the range 1...10000.
522 This controls the CPUWeight= and IOWeight= settings of the per-user
523 systemd slice unit user-$UID.slice. See systemd.resource-control(5)
524 for further details.
525 --storage=STORAGE
527 Selects the storage mechanism to use for this home directory. Takes
528 one of "luks", "fscrypt", "directory", "subvolume", "cifs". For
529 details about these mechanisms, see above. If a new home directory
530 is created and the storage type is not specifically specified,
531 homed.conf(5) defines which default storage to use.
532 --image-path=PATH
534 Takes a file system path. Configures where to place the user's home
535 directory. When LUKS2 storage is used refers to the path to the
536 loopback file, otherwise to the path to the home directory (which
537 may be in /home/ or any other accessible filesystem). When
538 unspecified defaults to /home/$USER.home when LUKS storage is used
539 and /home/$USER.homedir for the other storage mechanisms. Not
540 defined for the "cifs" storage mechanism. To use LUKS2 storage on a
541 regular block device (for example a USB stick) pass the path to the
542 block device here. Specifying the path to a directory here when
543 using LUKS2 storage is not allowed. Similar, specifying the path to
544 a regular file or device node is not allowed if any of the other
545 storage backends are used.
546 --drop-caches=BOOL
548 Automatically flush OS file system caches on logout. This is useful
549 in combination with the fscrypt storage backend to ensure the OS
550 does not keep decrypted versions of the files and directories in
551 memory (and accessible) after logout. This option is also supported
552 on other backends, but should not bring any benefit there. Defaults
553 to off, except if the selected storage backend is fscrypt, where it
554 defaults to on. Note that flushing OS caches will negatively
555 influence performance of the OS shortly after logout.
556 --fs-type=TYPE
558 When LUKS2 storage is used configures the file system type to use
559 inside the home directory LUKS2 container. One of "btrfs", "ext4",
560 "xfs". If not specified homed.conf(5) defines which default file
561 system type to use. Note that "xfs" is not recommended as its
562 support for file system resizing is too limited.
563 --luks-discard=BOOL
565 When LUKS2 storage is used configures whether to enable the
566 "discard" feature of the file system. If enabled the file system on
567 top of the LUKS2 volume will report empty block information to
568 LUKS2 and the loopback file below, ensuring that empty space in the
569 home directory is returned to the backing file system below the
570 LUKS2 volume, resulting in a "sparse" loopback file. This option
571 mostly defaults to off, since this permits over-committing home
572 directories which results in I/O errors if the underlying file
573 system runs full while the upper file system wants to allocate a
574 block. Such I/O errors are generally not handled well by file
575 systems nor applications. When LUKS2 storage is used on top of
576 regular block devices (instead of on top a loopback file) the
577 discard logic defaults to on.
578 --luks-offline-discard=BOOL
580 Similar to --luks-discard=, controls the trimming of the file
581 system. However, while --luks-discard= controls what happens when
582 the home directory is active, --luks-offline-discard= controls what
583 happens when it becomes inactive, i.e. whether to trim/allocate the
584 storage when deactivating the home directory. This option defaults
585 to on, to ensure disk space is minimized while a user is not logged
586 in.
587 --luks-extra-mount-options=OPTIONS
589 Takes a string containing additional mount options to use when
590 mounting the LUKS volume. If specified, this string will be
591 appended to the default, built-in mount options.
592 --luks-cipher=CIPHER, --luks-cipher-mode=MODE,
594 --luks-volume-key-size=BYTES, --luks-pbkdf-type=TYPE,
595 --luks-pbkdf-hash-algorithm=ALGORITHM, --luks-pbkdf-time-cost=SECONDS,
596 --luks-pbkdf-memory-cost=BYTES, --luks-pbkdf-parallel-threads=THREADS
597 Configures various cryptographic parameters for the LUKS2 storage
598 mechanism. See cryptsetup(8) for details on the specific
599 attributes.
600 Note that homectl uses bytes for key size, like /proc/crypto, but
602 cryptsetup(8) uses bits.
603 --auto-resize-mode=
605 Configures whether to automatically grow and/or shrink the backing
606 file system on login and logout. Takes one of the strings "off",
607 "grow", "shrink-and-grow". Only applies to the LUKS2 backend
608 currently, and if the btrfs file system is used inside it (since
609 only then online growing/shrinking of the file system is
610 supported). Defaults to "shrink-and-grow", if LUKS2/btrfs is used,
611 otherwise is off. If set to "off" no automatic shrinking/growing
612 during login or logout is done. If set to "grow" the home area is
613 grown to the size configured via --disk-size= should it currently
614 be smaller. If it already matches the configured size or is larger
615 no operation is executed. If set to "shrink-and-grow" the home area
616 is also resized during logout to the minimal size the used disk
617 space and file system constraints permit. This mode thus ensures
618 that while a home area is activated it is sized to the configured
619 size, but while deactivated it is compacted taking up only the
620 minimal space possible. Note that if the system is powered off
621 abnormally or if the user otherwise not logged out cleanly the
622 shrinking operation will not take place, and the user has to
623 re-login/logout again before it is executed again.
624 --rebalance-weight=
626 Configures the weight parameter for the free disk space rebalancing
627 logic. Only applies to the LUKS2 backend (since for the LUKS2
628 backend disk space is allocated from a per-user loopback file
629 system instead of immediately from a common pool like the other
630 backends do it). In regular intervals free disk space in the active
631 home areas and their backing storage is redistributed among them,
632 taking the weight value configured here into account. Expects an
633 integer in the range 1...10000, or the special string "off". If not
634 specified defaults to 100. The weight is used to scale free space
635 made available to the home areas: a home area with a weight of 200
636 will get twice the free space as one with a weight of 100; a home
637 area with a weight of 50 will get half of that. The backing file
638 system will be assigned space for a weight of 20. If set to "off"
639 no automatic free space distribution is done for this home area.
640 Note that resizing the home area explicitly (with homectl resize
641 see below) will implicitly turn off the automatic rebalancing. To
642 reenable the automatic rebalancing use --rebalance-weight= with an
643 empty parameter.
644 --nosuid=BOOL, --nodev=BOOL, --noexec=BOOL
646 Configures the "nosuid", "nodev" and "noexec" mount options for the
647 home directories. By default "nodev" and "nosuid" are on, while
648 "noexec" is off. For details about these mount options see
649 mount(8).
650 --cifs-domain=DOMAIN, --cifs-user-name=USER, --cifs-service=SERVICE,
652 --cifs-extra-mount-options=OPTIONS
653 Configures the Windows File Sharing (CIFS) domain and user to
654 associate with the home directory/user account, as well as the file
655 share ("service") to mount as directory. The latter is used when
656 "cifs" storage is selected. The file share should be specified in
657 format "//host/share/directory/...". The directory part is optional
658 — if not specified the home directory will be placed in the
659 top-level directory of the share. The --cifs-extra-mount-options=
660 setting allows specifying additional mount options when mounting
661 the share, see mount.cifs(8) for details.
662 --stop-delay=SECS
664 Configures the time the per-user service manager shall continue to
665 run after the all sessions of the user ended. The default is
666 configured in logind.conf(5) (for home directories of LUKS2 storage
667 located on removable media this defaults to 0 though). A longer
668 time makes sure quick, repetitive logins are more efficient as the
669 user's service manager doesn't have to be started every time.
670 --kill-processes=BOOL
672 Configures whether to kill all processes of the user on logout. The
673 default is configured in logind.conf(5).
674 --auto-login=BOOL
676 Takes a boolean argument. Configures whether the graphical UI of
677 the system should automatically log this user in if possible.
678 Defaults to off. If less or more than one user is marked this way
679 automatic login is disabled.
680
682 The following commands are understood:
683 list
685 List all home directories (along with brief details) currently
686 managed by systemd-homed.service. This command is also executed if
687 none is specified on the command line. (Note that the list of users
688 shown by this command does not include users managed by other
689 subsystems, such as system users or any traditional users listed in
690 /etc/passwd.)
691 activate USER [USER...]
693 Activate one or more home directories. The home directories of each
694 listed user will be activated and made available under their mount
695 points (typically in /home/$USER). Note that any home activated
696 this way stays active indefinitely, until it is explicitly
697 deactivated again (with deactivate, see below), or the user logs in
698 and out again and it thus is deactivated due to the automatic
699 deactivation-on-logout logic.
700 Activation of a home directory involves various operations that
702 depend on the selected storage mechanism. If the LUKS2 mechanism is
703 used, this generally involves: inquiring the user for a password,
704 setting up a loopback device, validating and activating the LUKS2
705 volume, checking the file system, mounting the file system, and
706 potentially changing the ownership of all included files to the
707 correct UID/GID.
708 deactivate USER [USER...]
710 Deactivate one or more home directories. This undoes the effect of
711 activate.
712 inspect USER [USER...]
714 Show various details about the specified home directories. This
715 shows various information about the home directory and its user
716 account, including runtime data such as current state, disk use and
717 similar. Combine with --json= to show the detailed JSON user record
718 instead, possibly combined with --export-format= to suppress
719 certain aspects of the output.
720 authenticate USER [USER...]
722 Validate authentication credentials of a home directory. This
723 queries the caller for a password (or similar) and checks that it
724 correctly unlocks the home directory. This leaves the home
725 directory in the state it is in, i.e. it leaves the home directory
726 in inactive state if it was inactive before, and in active state if
727 it was active before.
728 create USER, create --identity=PATH [USER]
730 Create a new home directory/user account of the specified name. Use
731 the various user record property options (as documented above) to
732 control various aspects of the home directory and its user
733 accounts.
734 The specified user name should follow the strict syntax described
736 on User/Group Name Syntax[3].
737 remove USER
739 Remove a home directory/user account. This will remove both the
740 home directory's user record and the home directory itself, and
741 thus delete all files and directories owned by the user.
742 update USER, update --identity=PATH [USER]
744 Update a home directory/user account. Use the various user record
745 property options (as documented above) to make changes to the
746 account, or alternatively provide a full, updated JSON user record
747 via the --identity= option.
748 Note that changes to user records not signed by a cryptographic
750 private key available locally are not permitted, unless --identity=
751 is used with a user record that is already correctly signed by a
752 recognized private key.
753 passwd USER
755 Change the password of the specified home directory/user account.
756 resize USER BYTES
758 Change the disk space assigned to the specified home directory. If
759 the LUKS2 storage mechanism is used this will automatically resize
760 the loopback file and the file system contained within. Note that
761 if "ext4" is used inside of the LUKS2 volume, it is necessary to
762 deactivate the home directory before shrinking it (i.e the user has
763 to log out). Growing can be done while the home directory is
764 active. If "xfs" is used inside of the LUKS2 volume the home
765 directory may not be shrunk whatsoever. On all three of "ext4",
766 "xfs" and "btrfs" the home directory may be grown while the user is
767 logged in, and on the latter also shrunk while the user is logged
768 in. If the "subvolume", "directory", "fscrypt" storage mechanisms
769 are used, resizing will change file system quota. The size
770 parameter may make use of the usual suffixes B, K, M, G, T (to the
771 base of 1024). The special strings "min" and "max" may be specified
772 in place of a numeric size value, for minimizing or maximizing disk
773 space assigned to the home area, taking constraints of the file
774 system, disk usage inside the home area and on the backing storage
775 into account.
776 lock USER
778 Temporarily suspend access to the user's home directory and remove
779 any associated cryptographic keys from memory. Any attempts to
780 access the user's home directory will stall until the home
781 directory is unlocked again (i.e. re-authenticated). This
782 functionality is primarily intended to be used during system
783 suspend to make sure the user's data cannot be accessed until the
784 user re-authenticates on resume. This operation is only defined for
785 home directories that use the LUKS2 storage mechanism.
786 unlock USER
788 Resume access to the user's home directory again, undoing the
789 effect of lock above. This requires authentication of the user, as
790 the cryptographic keys required for access to the home directory
791 need to be reacquired.
792 lock-all
794 Execute the lock command on all suitable home directories at once.
795 This operation is generally executed on system suspend (i.e. by
796 systemctl suspend and related commands), to ensure all active
797 user's cryptographic keys for accessing their home directories are
798 removed from memory.
799 deactivate-all
801 Execute the deactivate command on all active home directories at
802 once. This operation is generally executed on system shut down
803 (i.e. by systemctl poweroff and related commands), to ensure all
804 active user's home directories are fully deactivated before /home/
805 and related file systems are unmounted.
806 with USER COMMAND...
808 Activate the specified user's home directory, run the specified
809 command (under the caller's identity, not the specified user's) and
810 deactivate the home directory afterwards again (unless the user is
811 logged in otherwise). This command is useful for running privileged
812 backup scripts and such, but requires authentication with the
813 user's credentials in order to be able to unlock the user's home
814 directory.
815 rebalance
817 Rebalance free disk space between active home areas and the backing
818 storage. See --rebalance-weight= above. This executes no operation
819 unless there's at least one active LUKS2 home area that has disk
820 space rebalancing enabled. This operation is synchronous: it will
821 only complete once disk space is rebalanced according to the
822 rebalancing weights. Note that rebalancing also takes place
823 automatically in the background in regular intervals. Use this
824 command to synchronously ensure disk space is properly
825 redistributed before initiating an operation requiring large
826 amounts of disk space.
827
829 On success, 0 is returned, a non-zero failure code otherwise.
830 When a command is invoked with with, the exit status of the child is
832 propagated. Effectively, homectl will exit without error if the command
833 is successfully invoked and finishes successfully.
834
836 $SYSTEMD_LOG_LEVEL
837 The maximum log level of emitted messages (messages with a higher
838 log level, i.e. less important ones, will be suppressed). Either
839 one of (in order of decreasing importance) emerg, alert, crit, err,
840 warning, notice, info, debug, or an integer in the range 0...7. See
841 syslog(3) for more information.
842 $SYSTEMD_LOG_COLOR
844 A boolean. If true, messages written to the tty will be colored
845 according to priority.
846 This setting is only useful when messages are written directly to
848 the terminal, because journalctl(1) and other tools that display
849 logs will color messages based on the log level on their own.
850 $SYSTEMD_LOG_TIME
852 A boolean. If true, console log messages will be prefixed with a
853 timestamp.
854 This setting is only useful when messages are written directly to
856 the terminal or a file, because journalctl(1) and other tools that
857 display logs will attach timestamps based on the entry metadata on
858 their own.
859 $SYSTEMD_LOG_LOCATION
861 A boolean. If true, messages will be prefixed with a filename and
862 line number in the source code where the message originates.
863 Note that the log location is often attached as metadata to journal
865 entries anyway. Including it directly in the message text can
866 nevertheless be convenient when debugging programs.
867 $SYSTEMD_LOG_TID
869 A boolean. If true, messages will be prefixed with the current
870 numerical thread ID (TID).
871 Note that the this information is attached as metadata to journal
873 entries anyway. Including it directly in the message text can
874 nevertheless be convenient when debugging programs.
875 $SYSTEMD_LOG_TARGET
877 The destination for log messages. One of console (log to the
878 attached tty), console-prefixed (log to the attached tty but with
879 prefixes encoding the log level and "facility", see syslog(3), kmsg
880 (log to the kernel circular log buffer), journal (log to the
881 journal), journal-or-kmsg (log to the journal if available, and to
882 kmsg otherwise), auto (determine the appropriate log target
883 automatically, the default), null (disable log output).
884 $SYSTEMD_PAGER
886 Pager to use when --no-pager is not given; overrides $PAGER. If
887 neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known
888 pager implementations are tried in turn, including less(1) and
889 more(1), until one is found. If no pager implementation is
890 discovered no pager is invoked. Setting this environment variable
891 to an empty string or the value "cat" is equivalent to passing
892 --no-pager.
893 Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER (as well
895 as $PAGER) will be silently ignored.
896 $SYSTEMD_LESS
898 Override the options passed to less (by default "FRSXMK").
899 Users might want to change two options in particular:
901 K
903 This option instructs the pager to exit immediately when Ctrl+C
904 is pressed. To allow less to handle Ctrl+C itself to switch
905 back to the pager command prompt, unset this option.
906 If the value of $SYSTEMD_LESS does not include "K", and the
908 pager that is invoked is less, Ctrl+C will be ignored by the
909 executable, and needs to be handled by the pager.
910 X
912 This option instructs the pager to not send termcap
913 initialization and deinitialization strings to the terminal. It
914 is set by default to allow command output to remain visible in
915 the terminal even after the pager exits. Nevertheless, this
916 prevents some pager functionality from working, in particular
917 paged output cannot be scrolled with the mouse.
918 See less(1) for more discussion.
920 $SYSTEMD_LESSCHARSET
922 Override the charset passed to less (by default "utf-8", if the
923 invoking terminal is determined to be UTF-8 compatible).
924 $SYSTEMD_PAGERSECURE
926 Takes a boolean argument. When true, the "secure" mode of the pager
927 is enabled; if false, disabled. If $SYSTEMD_PAGERSECURE is not set
928 at all, secure mode is enabled if the effective UID is not the same
929 as the owner of the login session, see geteuid(2) and
930 sd_pid_get_owner_uid(3). In secure mode, LESSSECURE=1 will be set
931 when invoking the pager, and the pager shall disable commands that
932 open or create new files or start new subprocesses. When
933 $SYSTEMD_PAGERSECURE is not set at all, pagers which are not known
934 to implement secure mode will not be used. (Currently only less(1)
935 implements secure mode.)
936 Note: when commands are invoked with elevated privileges, for
938 example under sudo(8) or pkexec(1), care must be taken to ensure
939 that unintended interactive features are not enabled. "Secure" mode
940 for the pager may be enabled automatically as describe above.
941 Setting SYSTEMD_PAGERSECURE=0 or not removing it from the inherited
942 environment allows the user to invoke arbitrary commands. Note that
943 if the $SYSTEMD_PAGER or $PAGER variables are to be honoured,
944 $SYSTEMD_PAGERSECURE must be set too. It might be reasonable to
945 completely disable the pager using --no-pager instead.
946 $SYSTEMD_COLORS
948 Takes a boolean argument. When true, systemd and related utilities
949 will use colors in their output, otherwise the output will be
950 monochrome. Additionally, the variable can take one of the
951 following special values: "16", "256" to restrict the use of colors
952 to the base 16 or 256 ANSI colors, respectively. This can be
953 specified to override the automatic decision based on $TERM and
954 what the console is connected to.
955 $SYSTEMD_URLIFY
957 The value must be a boolean. Controls whether clickable links
958 should be generated in the output for terminal emulators supporting
959 this. This can be specified to override the decision that systemd
960 makes based on $TERM and other conditions.
961
963 Example 1. Create a user "waldo" in the administrator group "wheel",
964 and assign 500 MiB disk space to them.
965 homectl create waldo --real-name="Waldo McWaldo" -G wheel --disk-size=500M
967 Example 2. Create a user "wally" on a USB stick, and assign a maximum
969 of 500 concurrent tasks to them.
970 homectl create wally --real-name="Wally McWally" --image-path=/dev/disk/by-id/usb-SanDisk_Ultra_Fit_476fff954b2b5c44-0:0 --tasks-max=500
972 Example 3. Change nice level of user "odlaw" to +5 and make sure the
974 environment variable $SOME is set to the string "THING" for them on
975 login.
976 homectl update odlaw --nice=5 --setenv=SOME=THING
978 Example 4. Set up authentication with a YubiKey security token using
980 PKCS#11/PIV:
981 # Clear the Yubikey from any old keys (careful!)
983 ykman piv reset
984 # Generate a new private/public key pair on the device, store the public key in 'pubkey.pem'.
986 ykman piv generate-key -a RSA2048 9d pubkey.pem
987 # Create a self-signed certificate from this public key, and store it on the device.
989 ykman piv generate-certificate --subject "Knobelei" 9d pubkey.pem
990 # We don't need the public key on disk anymore
992 rm pubkey.pem
993 # Allow the security token to unlock the account of user 'lafcadio'.
995 homectl update lafcadio --pkcs11-token-uri=auto
996 Example 5. Set up authentication with a FIDO2 security token:
998 # Allow a FIDO2 security token to unlock the account of user 'nihilbaxter'.
1000 homectl update nihilbaxter --fido2-device=auto
1001
1003 systemd(1), systemd-homed.service(8), homed.conf(5), userdbctl(1),
1004 useradd(8), cryptsetup(8)
1005
1007 1. JSON User Records
1008 https://systemd.io/USER_RECORD
1009 2. Icon Naming Specification
1011 https://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html
1012 3. User/Group Name Syntax
1014 https://systemd.io/USER_NAMES
1015systemd 251 HOMECTL(1)