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f757855e | 1 | <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> |
8f7a3c14 | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
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4 | |
5 | <!-- | |
6 | This file is part of systemd. | |
7 | ||
8 | Copyright 2010 Lennart Poettering | |
9 | ||
10 | systemd is free software; you can redistribute it and/or modify it | |
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11 | under the terms of the GNU Lesser General Public License as published by |
12 | the Free Software Foundation; either version 2.1 of the License, or | |
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13 | (at your option) any later version. |
14 | ||
15 | systemd is distributed in the hope that it will be useful, but | |
16 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 18 | Lesser General Public License for more details. |
8f7a3c14 | 19 | |
5430f7f2 | 20 | You should have received a copy of the GNU Lesser General Public License |
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21 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
22 | --> | |
23 | ||
dfdebb1b | 24 | <refentry id="systemd-nspawn" |
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25 | xmlns:xi="http://www.w3.org/2001/XInclude"> |
26 | ||
27 | <refentryinfo> | |
28 | <title>systemd-nspawn</title> | |
29 | <productname>systemd</productname> | |
30 | ||
31 | <authorgroup> | |
32 | <author> | |
33 | <contrib>Developer</contrib> | |
34 | <firstname>Lennart</firstname> | |
35 | <surname>Poettering</surname> | |
36 | <email>lennart@poettering.net</email> | |
37 | </author> | |
38 | </authorgroup> | |
39 | </refentryinfo> | |
40 | ||
41 | <refmeta> | |
42 | <refentrytitle>systemd-nspawn</refentrytitle> | |
43 | <manvolnum>1</manvolnum> | |
44 | </refmeta> | |
45 | ||
46 | <refnamediv> | |
47 | <refname>systemd-nspawn</refname> | |
48 | <refpurpose>Spawn a namespace container for debugging, testing and building</refpurpose> | |
49 | </refnamediv> | |
50 | ||
51 | <refsynopsisdiv> | |
52 | <cmdsynopsis> | |
53 | <command>systemd-nspawn</command> | |
54 | <arg choice="opt" rep="repeat">OPTIONS</arg> | |
55 | <arg choice="opt"><replaceable>COMMAND</replaceable> | |
56 | <arg choice="opt" rep="repeat">ARGS</arg> | |
57 | </arg> | |
58 | </cmdsynopsis> | |
59 | <cmdsynopsis> | |
60 | <command>systemd-nspawn</command> | |
61 | <arg choice="plain">-b</arg> | |
62 | <arg choice="opt" rep="repeat">OPTIONS</arg> | |
63 | <arg choice="opt" rep="repeat">ARGS</arg> | |
64 | </cmdsynopsis> | |
65 | </refsynopsisdiv> | |
66 | ||
67 | <refsect1> | |
68 | <title>Description</title> | |
69 | ||
70 | <para><command>systemd-nspawn</command> may be used to run a | |
71 | command or OS in a light-weight namespace container. In many ways | |
72 | it is similar to | |
73 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
74 | but more powerful since it fully virtualizes the file system | |
75 | hierarchy, as well as the process tree, the various IPC subsystems | |
76 | and the host and domain name.</para> | |
77 | ||
78 | <para><command>systemd-nspawn</command> limits access to various | |
79 | kernel interfaces in the container to read-only, such as | |
80 | <filename>/sys</filename>, <filename>/proc/sys</filename> or | |
81 | <filename>/sys/fs/selinux</filename>. Network interfaces and the | |
82 | system clock may not be changed from within the container. Device | |
83 | nodes may not be created. The host system cannot be rebooted and | |
84 | kernel modules may not be loaded from within the container.</para> | |
85 | ||
86 | <para>Note that even though these security precautions are taken | |
7de7ee62 | 87 | <command>systemd-nspawn</command> is not suitable for fully secure |
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88 | container setups. Many of the security features may be |
89 | circumvented and are hence primarily useful to avoid accidental | |
7de7ee62 | 90 | changes to the host system from the container.</para> |
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91 | |
92 | <para>In contrast to | |
93 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command> | |
94 | may be used to boot full Linux-based operating systems in a | |
95 | container.</para> | |
96 | ||
97 | <para>Use a tool like | |
98 | <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
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99 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
100 | or | |
101 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
102 | to set up an OS directory tree suitable as file system hierarchy | |
103 | for <command>systemd-nspawn</command> containers.</para> | |
104 | ||
105 | <para>Note that <command>systemd-nspawn</command> will mount file | |
106 | systems private to the container to <filename>/dev</filename>, | |
107 | <filename>/run</filename> and similar. These will not be visible | |
108 | outside of the container, and their contents will be lost when the | |
109 | container exits.</para> | |
110 | ||
111 | <para>Note that running two <command>systemd-nspawn</command> | |
112 | containers from the same directory tree will not make processes in | |
113 | them see each other. The PID namespace separation of the two | |
114 | containers is complete and the containers will share very few | |
115 | runtime objects except for the underlying file system. Use | |
116 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s | |
117 | <command>login</command> command to request an additional login | |
118 | prompt in a running container.</para> | |
119 | ||
120 | <para><command>systemd-nspawn</command> implements the | |
121 | <ulink | |
122 | url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container | |
123 | Interface</ulink> specification.</para> | |
124 | ||
125 | <para>As a safety check <command>systemd-nspawn</command> will | |
126 | verify the existence of <filename>/usr/lib/os-release</filename> | |
127 | or <filename>/etc/os-release</filename> in the container tree | |
128 | before starting the container (see | |
129 | <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>). | |
130 | It might be necessary to add this file to the container tree | |
131 | manually if the OS of the container is too old to contain this | |
132 | file out-of-the-box.</para> | |
133 | </refsect1> | |
134 | ||
135 | <refsect1> | |
136 | <title>Options</title> | |
137 | ||
138 | <para>If option <option>-b</option> is specified, the arguments | |
139 | are used as arguments for the init binary. Otherwise, | |
140 | <replaceable>COMMAND</replaceable> specifies the program to launch | |
141 | in the container, and the remaining arguments are used as | |
142 | arguments for this program. If <option>-b</option> is not used and | |
ff9b60f3 | 143 | no arguments are specified, a shell is launched in the |
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144 | container.</para> |
145 | ||
146 | <para>The following options are understood:</para> | |
147 | ||
148 | <variablelist> | |
149 | <varlistentry> | |
150 | <term><option>-D</option></term> | |
151 | <term><option>--directory=</option></term> | |
152 | ||
153 | <listitem><para>Directory to use as file system root for the | |
154 | container.</para> | |
155 | ||
156 | <para>If neither <option>--directory=</option>, nor | |
157 | <option>--image=</option> is specified the directory is | |
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158 | determined by searching for a directory named the same as the |
159 | machine name specified with <option>--machine=</option>. See | |
160 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
161 | section "Files and Directories" for the precise search path.</para> | |
162 | ||
163 | <para>If neither <option>--directory=</option>, | |
164 | <option>--image=</option>, nor <option>--machine=</option> | |
165 | are specified, the current directory will | |
166 | be used. May not be specified together with | |
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167 | <option>--image=</option>.</para></listitem> |
168 | </varlistentry> | |
169 | ||
170 | <varlistentry> | |
171 | <term><option>--template=</option></term> | |
172 | ||
173 | <listitem><para>Directory or <literal>btrfs</literal> | |
174 | subvolume to use as template for the container's root | |
175 | directory. If this is specified and the container's root | |
176 | directory (as configured by <option>--directory=</option>) | |
177 | does not yet exist it is created as <literal>btrfs</literal> | |
178 | subvolume and populated from this template tree. Ideally, the | |
179 | specified template path refers to the root of a | |
180 | <literal>btrfs</literal> subvolume, in which case a simple | |
181 | copy-on-write snapshot is taken, and populating the root | |
182 | directory is instant. If the specified template path does not | |
183 | refer to the root of a <literal>btrfs</literal> subvolume (or | |
184 | not even to a <literal>btrfs</literal> file system at all), | |
185 | the tree is copied, which can be substantially more | |
186 | time-consuming. Note that if this option is used the | |
187 | container's root directory (in contrast to the template | |
188 | directory!) must be located on a <literal>btrfs</literal> file | |
189 | system, so that the <literal>btrfs</literal> subvolume may be | |
190 | created. May not be specified together with | |
191 | <option>--image=</option> or | |
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192 | <option>--ephemeral</option>.</para> |
193 | ||
194 | <para>Note that this switch leaves host name, machine ID and | |
195 | all other settings that could identify the instance | |
196 | unmodified.</para></listitem> | |
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197 | </varlistentry> |
198 | ||
199 | <varlistentry> | |
200 | <term><option>-x</option></term> | |
201 | <term><option>--ephemeral</option></term> | |
202 | ||
203 | <listitem><para>If specified, the container is run with a | |
204 | temporary <literal>btrfs</literal> snapshot of its root | |
205 | directory (as configured with <option>--directory=</option>), | |
206 | that is removed immediately when the container terminates. | |
207 | This option is only supported if the root file system is | |
208 | <literal>btrfs</literal>. May not be specified together with | |
209 | <option>--image=</option> or | |
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210 | <option>--template=</option>.</para> |
211 | <para>Note that this switch leaves host name, machine ID and | |
212 | all other settings that could identify the instance | |
213 | unmodified.</para></listitem> | |
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214 | </varlistentry> |
215 | ||
216 | <varlistentry> | |
217 | <term><option>-i</option></term> | |
218 | <term><option>--image=</option></term> | |
219 | ||
220 | <listitem><para>Disk image to mount the root directory for the | |
221 | container from. Takes a path to a regular file or to a block | |
222 | device node. The file or block device must contain | |
223 | either:</para> | |
224 | ||
225 | <itemizedlist> | |
226 | <listitem><para>An MBR partition table with a single | |
227 | partition of type 0x83 that is marked | |
228 | bootable.</para></listitem> | |
229 | ||
230 | <listitem><para>A GUID partition table (GPT) with a single | |
231 | partition of type | |
232 | 0fc63daf-8483-4772-8e79-3d69d8477de4.</para></listitem> | |
233 | ||
234 | <listitem><para>A GUID partition table (GPT) with a marked | |
235 | root partition which is mounted as the root directory of the | |
236 | container. Optionally, GPT images may contain a home and/or | |
237 | a server data partition which are mounted to the appropriate | |
238 | places in the container. All these partitions must be | |
239 | identified by the partition types defined by the <ulink | |
240 | url="http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable | |
241 | Partitions Specification</ulink>.</para></listitem> | |
242 | </itemizedlist> | |
243 | ||
244 | <para>Any other partitions, such as foreign partitions, swap | |
245 | partitions or EFI system partitions are not mounted. May not | |
246 | be specified together with <option>--directory=</option>, | |
247 | <option>--template=</option> or | |
248 | <option>--ephemeral</option>.</para></listitem> | |
249 | </varlistentry> | |
250 | ||
251 | <varlistentry> | |
252 | <term><option>-b</option></term> | |
253 | <term><option>--boot</option></term> | |
254 | ||
255 | <listitem><para>Automatically search for an init binary and | |
256 | invoke it instead of a shell or a user supplied program. If | |
257 | this option is used, arguments specified on the command line | |
258 | are used as arguments for the init binary. This option may not | |
259 | be combined with <option>--share-system</option>. | |
260 | </para></listitem> | |
261 | </varlistentry> | |
262 | ||
263 | <varlistentry> | |
264 | <term><option>-u</option></term> | |
265 | <term><option>--user=</option></term> | |
266 | ||
267 | <listitem><para>After transitioning into the container, change | |
268 | to the specified user-defined in the container's user | |
269 | database. Like all other systemd-nspawn features, this is not | |
270 | a security feature and provides protection against accidental | |
271 | destructive operations only.</para></listitem> | |
272 | </varlistentry> | |
273 | ||
274 | <varlistentry> | |
275 | <term><option>-M</option></term> | |
276 | <term><option>--machine=</option></term> | |
277 | ||
278 | <listitem><para>Sets the machine name for this container. This | |
279 | name may be used to identify this container during its runtime | |
280 | (for example in tools like | |
281 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
282 | and similar), and is used to initialize the container's | |
283 | hostname (which the container can choose to override, | |
284 | however). If not specified, the last component of the root | |
285 | directory path of the container is used, possibly suffixed | |
286 | with a random identifier in case <option>--ephemeral</option> | |
287 | mode is selected. If the root directory selected is the host's | |
288 | root directory the host's hostname is used as default | |
289 | instead.</para></listitem> | |
290 | </varlistentry> | |
291 | ||
292 | <varlistentry> | |
293 | <term><option>--uuid=</option></term> | |
294 | ||
295 | <listitem><para>Set the specified UUID for the container. The | |
296 | init system will initialize | |
297 | <filename>/etc/machine-id</filename> from this if this file is | |
298 | not set yet. </para></listitem> | |
299 | </varlistentry> | |
300 | ||
301 | <varlistentry> | |
302 | <term><option>--slice=</option></term> | |
303 | ||
304 | <listitem><para>Make the container part of the specified | |
305 | slice, instead of the default | |
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306 | <filename>machine.slice</filename>. This is only applies if |
307 | the machine is run in its own scope unit, i.e. if | |
308 | <option>--keep-unit</option> is not used.</para> | |
309 | </listitem> | |
310 | </varlistentry> | |
311 | ||
312 | <varlistentry> | |
313 | <term><option>--property=</option></term> | |
314 | ||
315 | <listitem><para>Set a unit property on the scope unit to | |
316 | register for the machine. This only applies if the machine is | |
317 | run in its own scope unit, i.e. if | |
318 | <option>--keep-unit</option> is not used. Takes unit property | |
319 | assignments in the same format as <command>systemctl | |
320 | set-property</command>. This is useful to set memory limits | |
321 | and similar for machines.</para> | |
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322 | </listitem> |
323 | </varlistentry> | |
324 | ||
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325 | <varlistentry> |
326 | <term><option>--private-users=</option></term> | |
327 | ||
b938cb90 | 328 | <listitem><para>Enables user namespacing. If enabled, the |
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329 | container will run with its own private set of Unix user and |
330 | group ids (UIDs and GIDs). Takes none, one or two | |
331 | colon-separated parameters: the first parameter specifies the | |
332 | first host UID to assign to the container, the second | |
333 | parameter specifies the number of host UIDs to assign to the | |
334 | container. If the second parameter is omitted, 65536 UIDs are | |
7c918141 | 335 | assigned. If the first parameter is also omitted (and hence |
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336 | no parameter passed at all), the first UID assigned to the |
337 | container is read from the owner of the root directory of the | |
b938cb90 | 338 | container's directory tree. By default, no user namespacing is |
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339 | applied.</para> |
340 | ||
341 | <para>Note that user namespacing currently requires OS trees | |
342 | that are prepared for the UID shift that is being applied: | |
343 | UIDs and GIDs used for file ownership or in file ACL entries | |
344 | must be shifted to the container UID base that is | |
345 | used during container runtime.</para> | |
346 | ||
a8eaaee7 | 347 | <para>It is recommended to assign at least 65536 UIDs to each |
03cfe0d5 | 348 | container, so that the usable UID range in the container |
b938cb90 | 349 | covers 16 bit. For best security, do not assign overlapping UID |
03cfe0d5 | 350 | ranges to multiple containers. It is hence a good idea to use |
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351 | the upper 16 bit of the host 32-bit UIDs as container |
352 | identifier, while the lower 16 bit encode the container UID | |
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353 | used.</para> |
354 | ||
b938cb90 | 355 | <para>When user namespaces are used, the GID range assigned to |
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356 | each container is always chosen identical to the UID |
357 | range.</para></listitem> | |
358 | </varlistentry> | |
359 | ||
360 | ||
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361 | <varlistentry> |
362 | <term><option>--private-network</option></term> | |
363 | ||
364 | <listitem><para>Disconnect networking of the container from | |
365 | the host. This makes all network interfaces unavailable in the | |
366 | container, with the exception of the loopback device and those | |
367 | specified with <option>--network-interface=</option> and | |
368 | configured with <option>--network-veth</option>. If this | |
369 | option is specified, the CAP_NET_ADMIN capability will be | |
370 | added to the set of capabilities the container retains. The | |
371 | latter may be disabled by using | |
372 | <option>--drop-capability=</option>.</para></listitem> | |
373 | </varlistentry> | |
374 | ||
375 | <varlistentry> | |
376 | <term><option>--network-interface=</option></term> | |
377 | ||
378 | <listitem><para>Assign the specified network interface to the | |
379 | container. This will remove the specified interface from the | |
380 | calling namespace and place it in the container. When the | |
381 | container terminates, it is moved back to the host namespace. | |
382 | Note that <option>--network-interface=</option> implies | |
383 | <option>--private-network</option>. This option may be used | |
384 | more than once to add multiple network interfaces to the | |
385 | container.</para></listitem> | |
386 | </varlistentry> | |
387 | ||
388 | <varlistentry> | |
389 | <term><option>--network-macvlan=</option></term> | |
390 | ||
391 | <listitem><para>Create a <literal>macvlan</literal> interface | |
392 | of the specified Ethernet network interface and add it to the | |
393 | container. A <literal>macvlan</literal> interface is a virtual | |
394 | interface that adds a second MAC address to an existing | |
395 | physical Ethernet link. The interface in the container will be | |
396 | named after the interface on the host, prefixed with | |
397 | <literal>mv-</literal>. Note that | |
398 | <option>--network-macvlan=</option> implies | |
399 | <option>--private-network</option>. This option may be used | |
400 | more than once to add multiple network interfaces to the | |
401 | container.</para></listitem> | |
402 | </varlistentry> | |
403 | ||
404 | <varlistentry> | |
405 | <term><option>--network-ipvlan=</option></term> | |
406 | ||
407 | <listitem><para>Create an <literal>ipvlan</literal> interface | |
408 | of the specified Ethernet network interface and add it to the | |
409 | container. An <literal>ipvlan</literal> interface is a virtual | |
410 | interface, similar to a <literal>macvlan</literal> interface, | |
411 | which uses the same MAC address as the underlying interface. | |
412 | The interface in the container will be named after the | |
413 | interface on the host, prefixed with <literal>iv-</literal>. | |
414 | Note that <option>--network-ipvlan=</option> implies | |
415 | <option>--private-network</option>. This option may be used | |
416 | more than once to add multiple network interfaces to the | |
417 | container.</para></listitem> | |
418 | </varlistentry> | |
419 | ||
420 | <varlistentry> | |
421 | <term><option>-n</option></term> | |
422 | <term><option>--network-veth</option></term> | |
423 | ||
424 | <listitem><para>Create a virtual Ethernet link | |
425 | (<literal>veth</literal>) between host and container. The host | |
426 | side of the Ethernet link will be available as a network | |
427 | interface named after the container's name (as specified with | |
428 | <option>--machine=</option>), prefixed with | |
429 | <literal>ve-</literal>. The container side of the Ethernet | |
430 | link will be named <literal>host0</literal>. Note that | |
431 | <option>--network-veth</option> implies | |
432 | <option>--private-network</option>.</para></listitem> | |
433 | </varlistentry> | |
434 | ||
435 | <varlistentry> | |
436 | <term><option>--network-bridge=</option></term> | |
437 | ||
438 | <listitem><para>Adds the host side of the Ethernet link | |
439 | created with <option>--network-veth</option> to the specified | |
440 | bridge. Note that <option>--network-bridge=</option> implies | |
441 | <option>--network-veth</option>. If this option is used, the | |
442 | host side of the Ethernet link will use the | |
443 | <literal>vb-</literal> prefix instead of | |
444 | <literal>ve-</literal>.</para></listitem> | |
445 | </varlistentry> | |
446 | ||
447 | <varlistentry> | |
448 | <term><option>-p</option></term> | |
449 | <term><option>--port=</option></term> | |
450 | ||
451 | <listitem><para>If private networking is enabled, maps an IP | |
452 | port on the host onto an IP port on the container. Takes a | |
453 | protocol specifier (either <literal>tcp</literal> or | |
454 | <literal>udp</literal>), separated by a colon from a host port | |
455 | number in the range 1 to 65535, separated by a colon from a | |
456 | container port number in the range from 1 to 65535. The | |
457 | protocol specifier and its separating colon may be omitted, in | |
458 | which case <literal>tcp</literal> is assumed. The container | |
7c918141 | 459 | port number and its colon may be omitted, in which case the |
798d3a52 | 460 | same port as the host port is implied. This option is only |
a8eaaee7 | 461 | supported if private networking is used, such as with |
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462 | <option>--network-veth</option> or |
463 | <option>--network-bridge=</option>.</para></listitem> | |
464 | </varlistentry> | |
465 | ||
466 | <varlistentry> | |
467 | <term><option>-Z</option></term> | |
468 | <term><option>--selinux-context=</option></term> | |
469 | ||
470 | <listitem><para>Sets the SELinux security context to be used | |
471 | to label processes in the container.</para> | |
472 | </listitem> | |
473 | </varlistentry> | |
474 | ||
475 | <varlistentry> | |
476 | <term><option>-L</option></term> | |
477 | <term><option>--selinux-apifs-context=</option></term> | |
478 | ||
479 | <listitem><para>Sets the SELinux security context to be used | |
480 | to label files in the virtual API file systems in the | |
481 | container.</para> | |
482 | </listitem> | |
483 | </varlistentry> | |
484 | ||
485 | <varlistentry> | |
486 | <term><option>--capability=</option></term> | |
487 | ||
488 | <listitem><para>List one or more additional capabilities to | |
489 | grant the container. Takes a comma-separated list of | |
490 | capability names, see | |
491 | <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
492 | for more information. Note that the following capabilities | |
493 | will be granted in any way: CAP_CHOWN, CAP_DAC_OVERRIDE, | |
494 | CAP_DAC_READ_SEARCH, CAP_FOWNER, CAP_FSETID, CAP_IPC_OWNER, | |
495 | CAP_KILL, CAP_LEASE, CAP_LINUX_IMMUTABLE, | |
496 | CAP_NET_BIND_SERVICE, CAP_NET_BROADCAST, CAP_NET_RAW, | |
497 | CAP_SETGID, CAP_SETFCAP, CAP_SETPCAP, CAP_SETUID, | |
498 | CAP_SYS_ADMIN, CAP_SYS_CHROOT, CAP_SYS_NICE, CAP_SYS_PTRACE, | |
499 | CAP_SYS_TTY_CONFIG, CAP_SYS_RESOURCE, CAP_SYS_BOOT, | |
500 | CAP_AUDIT_WRITE, CAP_AUDIT_CONTROL. Also CAP_NET_ADMIN is | |
501 | retained if <option>--private-network</option> is specified. | |
502 | If the special value <literal>all</literal> is passed, all | |
503 | capabilities are retained.</para></listitem> | |
504 | </varlistentry> | |
505 | ||
506 | <varlistentry> | |
507 | <term><option>--drop-capability=</option></term> | |
508 | ||
509 | <listitem><para>Specify one or more additional capabilities to | |
510 | drop for the container. This allows running the container with | |
511 | fewer capabilities than the default (see | |
512 | above).</para></listitem> | |
513 | </varlistentry> | |
514 | ||
c6c8f6e2 LP |
515 | <varlistentry> |
516 | <term><option>--kill-signal=</option></term> | |
517 | ||
518 | <listitem><para>Specify the process signal to send to the | |
519 | container's PID 1 when nspawn itself receives SIGTERM, in | |
520 | order to trigger an orderly shutdown of the | |
521 | container. Defaults to SIGRTMIN+3 if <option>--boot</option> | |
522 | is used (on systemd-compatible init systems SIGRTMIN+3 | |
523 | triggers an orderly shutdown). Takes a signal name like | |
524 | <literal>SIGHUP</literal>, <literal>SIGTERM</literal> or | |
525 | similar as argument.</para></listitem> | |
526 | </varlistentry> | |
527 | ||
798d3a52 ZJS |
528 | <varlistentry> |
529 | <term><option>--link-journal=</option></term> | |
530 | ||
531 | <listitem><para>Control whether the container's journal shall | |
532 | be made visible to the host system. If enabled, allows viewing | |
533 | the container's journal files from the host (but not vice | |
534 | versa). Takes one of <literal>no</literal>, | |
535 | <literal>host</literal>, <literal>try-host</literal>, | |
536 | <literal>guest</literal>, <literal>try-guest</literal>, | |
537 | <literal>auto</literal>. If <literal>no</literal>, the journal | |
538 | is not linked. If <literal>host</literal>, the journal files | |
539 | are stored on the host file system (beneath | |
540 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
541 | and the subdirectory is bind-mounted into the container at the | |
542 | same location. If <literal>guest</literal>, the journal files | |
543 | are stored on the guest file system (beneath | |
544 | <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>) | |
545 | and the subdirectory is symlinked into the host at the same | |
546 | location. <literal>try-host</literal> and | |
547 | <literal>try-guest</literal> do the same but do not fail if | |
548 | the host does not have persistent journalling enabled. If | |
549 | <literal>auto</literal> (the default), and the right | |
550 | subdirectory of <filename>/var/log/journal</filename> exists, | |
551 | it will be bind mounted into the container. If the | |
552 | subdirectory does not exist, no linking is performed. | |
553 | Effectively, booting a container once with | |
554 | <literal>guest</literal> or <literal>host</literal> will link | |
555 | the journal persistently if further on the default of | |
556 | <literal>auto</literal> is used.</para></listitem> | |
557 | </varlistentry> | |
558 | ||
559 | <varlistentry> | |
560 | <term><option>-j</option></term> | |
561 | ||
562 | <listitem><para>Equivalent to | |
563 | <option>--link-journal=try-guest</option>.</para></listitem> | |
564 | </varlistentry> | |
565 | ||
566 | <varlistentry> | |
567 | <term><option>--read-only</option></term> | |
568 | ||
569 | <listitem><para>Mount the root file system read-only for the | |
570 | container.</para></listitem> | |
571 | </varlistentry> | |
572 | ||
573 | <varlistentry> | |
574 | <term><option>--bind=</option></term> | |
575 | <term><option>--bind-ro=</option></term> | |
576 | ||
577 | <listitem><para>Bind mount a file or directory from the host | |
b938cb90 | 578 | into the container. Takes one of: a path argument — in which |
798d3a52 | 579 | case the specified path will be mounted from the host to the |
b938cb90 JE |
580 | same path in the container —, or a colon-separated pair of |
581 | paths — in which case the first specified path is the source | |
798d3a52 | 582 | in the host, and the second path is the destination in the |
b938cb90 JE |
583 | container —, or a colon-separated triple of source path, |
584 | destination path and mount options. Mount options are | |
585 | comma-separated and currently, only "rbind" and "norbind" | |
586 | are allowed. Defaults to "rbind". Backslash escapes are interpreted, so | |
8ef24e7a RM |
587 | <literal>\:</literal> may be used to embed colons in either path. |
588 | This option may be specified multiple times for | |
64b282ef LP |
589 | creating multiple independent bind mount points. The |
590 | <option>--bind-ro=</option> option creates read-only bind | |
591 | mounts.</para></listitem> | |
798d3a52 ZJS |
592 | </varlistentry> |
593 | ||
594 | <varlistentry> | |
595 | <term><option>--tmpfs=</option></term> | |
596 | ||
597 | <listitem><para>Mount a tmpfs file system into the container. | |
598 | Takes a single absolute path argument that specifies where to | |
599 | mount the tmpfs instance to (in which case the directory | |
600 | access mode will be chosen as 0755, owned by root/root), or | |
601 | optionally a colon-separated pair of path and mount option | |
b938cb90 | 602 | string that is used for mounting (in which case the kernel |
798d3a52 ZJS |
603 | default for access mode and owner will be chosen, unless |
604 | otherwise specified). This option is particularly useful for | |
605 | mounting directories such as <filename>/var</filename> as | |
606 | tmpfs, to allow state-less systems, in particular when | |
ffcd3e89 | 607 | combined with <option>--read-only</option>. |
b938cb90 | 608 | Backslash escapes are interpreted in the path, so |
ffcd3e89 RM |
609 | <literal>\:</literal> may be used to embed colons in the path. |
610 | </para></listitem> | |
798d3a52 ZJS |
611 | </varlistentry> |
612 | ||
5a8af538 LP |
613 | <varlistentry> |
614 | <term><option>--overlay=</option></term> | |
615 | <term><option>--overlay-ro=</option></term> | |
616 | ||
617 | <listitem><para>Combine multiple directory trees into one | |
618 | overlay file system and mount it into the container. Takes a | |
619 | list of colon-separated paths to the directory trees to | |
620 | combine and the destination mount point.</para> | |
621 | ||
2eadf91c RM |
622 | <para>Backslash escapes are interpreted in the paths, so |
623 | <literal>\:</literal> may be used to embed colons in the paths. | |
624 | </para> | |
625 | ||
5a8af538 LP |
626 | <para>If three or more paths are specified, then the last |
627 | specified path is the destination mount point in the | |
628 | container, all paths specified before refer to directory trees | |
629 | on the host and are combined in the specified order into one | |
630 | overlay file system. The left-most path is hence the lowest | |
631 | directory tree, the second-to-last path the highest directory | |
632 | tree in the stacking order. If <option>--overlay-ro=</option> | |
b938cb90 | 633 | is used instead of <option>--overlay=</option>, a read-only |
5a8af538 | 634 | overlay file system is created. If a writable overlay file |
b938cb90 | 635 | system is created, all changes made to it are written to the |
5a8af538 LP |
636 | highest directory tree in the stacking order, i.e. the |
637 | second-to-last specified.</para> | |
638 | ||
639 | <para>If only two paths are specified, then the second | |
640 | specified path is used both as the top-level directory tree in | |
641 | the stacking order as seen from the host, as well as the mount | |
642 | point for the overlay file system in the container. At least | |
643 | two paths have to be specified.</para> | |
644 | ||
645 | <para>For details about overlay file systems, see <ulink | |
646 | url="https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt">overlayfs.txt</ulink>. Note | |
647 | that the semantics of overlay file systems are substantially | |
648 | different from normal file systems, in particular regarding | |
649 | reported device and inode information. Device and inode | |
650 | information may change for a file while it is being written | |
651 | to, and processes might see out-of-date versions of files at | |
652 | times. Note that this switch automatically derives the | |
653 | <literal>workdir=</literal> mount option for the overlay file | |
654 | system from the top-level directory tree, making it a sibling | |
655 | of it. It is hence essential that the top-level directory tree | |
656 | is not a mount point itself (since the working directory must | |
657 | be on the same file system as the top-most directory | |
658 | tree). Also note that the <literal>lowerdir=</literal> mount | |
659 | option receives the paths to stack in the opposite order of | |
660 | this switch.</para></listitem> | |
661 | </varlistentry> | |
662 | ||
798d3a52 ZJS |
663 | <varlistentry> |
664 | <term><option>--setenv=</option></term> | |
665 | ||
666 | <listitem><para>Specifies an environment variable assignment | |
667 | to pass to the init process in the container, in the format | |
668 | <literal>NAME=VALUE</literal>. This may be used to override | |
669 | the default variables or to set additional variables. This | |
670 | parameter may be used more than once.</para></listitem> | |
671 | </varlistentry> | |
672 | ||
673 | <varlistentry> | |
674 | <term><option>--share-system</option></term> | |
675 | ||
676 | <listitem><para>Allows the container to share certain system | |
677 | facilities with the host. More specifically, this turns off | |
678 | PID namespacing, UTS namespacing and IPC namespacing, and thus | |
679 | allows the guest to see and interact more easily with | |
680 | processes outside of the container. Note that using this | |
681 | option makes it impossible to start up a full Operating System | |
682 | in the container, as an init system cannot operate in this | |
683 | mode. It is only useful to run specific programs or | |
684 | applications this way, without involving an init system in the | |
685 | container. This option implies <option>--register=no</option>. | |
686 | This option may not be combined with | |
687 | <option>--boot</option>.</para></listitem> | |
688 | </varlistentry> | |
689 | ||
690 | <varlistentry> | |
691 | <term><option>--register=</option></term> | |
692 | ||
693 | <listitem><para>Controls whether the container is registered | |
694 | with | |
695 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
a8eaaee7 | 696 | Takes a boolean argument, which defaults to <literal>yes</literal>. |
798d3a52 ZJS |
697 | This option should be enabled when the container runs a full |
698 | Operating System (more specifically: an init system), and is | |
699 | useful to ensure that the container is accessible via | |
700 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
701 | and shown by tools such as | |
702 | <citerefentry project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>. | |
703 | If the container does not run an init system, it is | |
704 | recommended to set this option to <literal>no</literal>. Note | |
705 | that <option>--share-system</option> implies | |
706 | <option>--register=no</option>. </para></listitem> | |
707 | </varlistentry> | |
708 | ||
709 | <varlistentry> | |
710 | <term><option>--keep-unit</option></term> | |
711 | ||
712 | <listitem><para>Instead of creating a transient scope unit to | |
713 | run the container in, simply register the service or scope | |
714 | unit <command>systemd-nspawn</command> has been invoked in | |
715 | with | |
716 | <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
717 | This has no effect if <option>--register=no</option> is used. | |
718 | This switch should be used if | |
719 | <command>systemd-nspawn</command> is invoked from within a | |
720 | service unit, and the service unit's sole purpose is to run a | |
721 | single <command>systemd-nspawn</command> container. This | |
722 | option is not available if run from a user | |
723 | session.</para></listitem> | |
724 | </varlistentry> | |
725 | ||
726 | <varlistentry> | |
727 | <term><option>--personality=</option></term> | |
728 | ||
729 | <listitem><para>Control the architecture ("personality") | |
730 | reported by | |
3ba3a79d | 731 | <citerefentry project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry> |
798d3a52 ZJS |
732 | in the container. Currently, only <literal>x86</literal> and |
733 | <literal>x86-64</literal> are supported. This is useful when | |
734 | running a 32-bit container on a 64-bit host. If this setting | |
735 | is not used, the personality reported in the container is the | |
736 | same as the one reported on the host.</para></listitem> | |
737 | </varlistentry> | |
738 | ||
739 | <varlistentry> | |
740 | <term><option>-q</option></term> | |
741 | <term><option>--quiet</option></term> | |
742 | ||
743 | <listitem><para>Turns off any status output by the tool | |
744 | itself. When this switch is used, the only output from nspawn | |
745 | will be the console output of the container OS | |
746 | itself.</para></listitem> | |
747 | </varlistentry> | |
748 | ||
749 | <varlistentry> | |
f757855e LP |
750 | <term><option>--volatile</option></term> |
751 | <term><option>--volatile=</option><replaceable>MODE</replaceable></term> | |
798d3a52 ZJS |
752 | |
753 | <listitem><para>Boots the container in volatile mode. When no | |
754 | mode parameter is passed or when mode is specified as | |
b938cb90 | 755 | <option>yes</option>, full volatile mode is enabled. This |
a8eaaee7 | 756 | means the root directory is mounted as a mostly unpopulated |
798d3a52 ZJS |
757 | <literal>tmpfs</literal> instance, and |
758 | <filename>/usr</filename> from the OS tree is mounted into it, | |
759 | read-only (the system thus starts up with read-only OS | |
760 | resources, but pristine state and configuration, any changes | |
761 | to the either are lost on shutdown). When the mode parameter | |
b938cb90 | 762 | is specified as <option>state</option>, the OS tree is |
798d3a52 | 763 | mounted read-only, but <filename>/var</filename> is mounted as |
a8eaaee7 | 764 | a <literal>tmpfs</literal> instance into it (the system thus |
798d3a52 | 765 | starts up with read-only OS resources and configuration, but |
a8eaaee7 | 766 | pristine state, and any changes to the latter are lost on |
798d3a52 | 767 | shutdown). When the mode parameter is specified as |
b938cb90 | 768 | <option>no</option> (the default), the whole OS tree is made |
798d3a52 ZJS |
769 | available writable.</para> |
770 | ||
f757855e LP |
771 | <para>Note that setting this to <option>yes</option> or |
772 | <option>state</option> will only work correctly with | |
798d3a52 ZJS |
773 | operating systems in the container that can boot up with only |
774 | <filename>/usr</filename> mounted, and are able to populate | |
775 | <filename>/var</filename> automatically, as | |
776 | needed.</para></listitem> | |
777 | </varlistentry> | |
778 | ||
f757855e LP |
779 | <varlistentry> |
780 | <term><option>--settings=</option><replaceable>MODE</replaceable></term> | |
781 | ||
782 | <listitem><para>Controls whether | |
783 | <command>systemd-nspawn</command> shall search for and use | |
784 | additional per-container settings from | |
785 | <filename>.nspawn</filename> files. Takes a boolean or the | |
786 | special values <option>override</option> or | |
787 | <option>trusted</option>.</para> | |
788 | ||
b938cb90 | 789 | <para>If enabled (the default), a settings file named after the |
f757855e LP |
790 | machine (as specified with the <option>--machine=</option> |
791 | setting, or derived from the directory or image file name) | |
792 | with the suffix <filename>.nspawn</filename> is searched in | |
793 | <filename>/etc/systemd/nspawn/</filename> and | |
794 | <filename>/run/systemd/nspawn/</filename>. If it is found | |
795 | there, its settings are read and used. If it is not found | |
b938cb90 | 796 | there, it is subsequently searched in the same directory as the |
f757855e | 797 | image file or in the immediate parent of the root directory of |
b938cb90 | 798 | the container. In this case, if the file is found, its settings |
f757855e | 799 | will be also read and used, but potentially unsafe settings |
b938cb90 | 800 | are ignored. Note that in both these cases, settings on the |
4f76ef04 | 801 | command line take precedence over the corresponding settings |
f757855e LP |
802 | from loaded <filename>.nspawn</filename> files, if both are |
803 | specified. Unsafe settings are considered all settings that | |
804 | elevate the container's privileges or grant access to | |
805 | additional resources such as files or directories of the | |
806 | host. For details about the format and contents of | |
b938cb90 | 807 | <filename>.nspawn</filename> files, consult |
f757855e LP |
808 | <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> |
809 | ||
b938cb90 JE |
810 | <para>If this option is set to <option>override</option>, the |
811 | file is searched, read and used the same way, however, the order of | |
f757855e LP |
812 | precedence is reversed: settings read from the |
813 | <filename>.nspawn</filename> file will take precedence over | |
814 | the corresponding command line options, if both are | |
815 | specified.</para> | |
816 | ||
b938cb90 | 817 | <para>If this option is set to <option>trusted</option>, the |
f757855e | 818 | file is searched, read and used the same way, but regardless |
a8eaaee7 | 819 | of being found in <filename>/etc/systemd/nspawn/</filename>, |
f757855e LP |
820 | <filename>/run/systemd/nspawn/</filename> or next to the image |
821 | file or container root directory, all settings will take | |
b938cb90 | 822 | effect, however, command line arguments still take precedence |
f757855e LP |
823 | over corresponding settings.</para> |
824 | ||
b938cb90 | 825 | <para>If disabled, no <filename>.nspawn</filename> file is read |
f757855e LP |
826 | and no settings except the ones on the command line are in |
827 | effect.</para></listitem> | |
828 | </varlistentry> | |
829 | ||
798d3a52 ZJS |
830 | <xi:include href="standard-options.xml" xpointer="help" /> |
831 | <xi:include href="standard-options.xml" xpointer="version" /> | |
832 | </variablelist> | |
833 | ||
834 | </refsect1> | |
835 | ||
836 | <refsect1> | |
837 | <title>Examples</title> | |
838 | ||
839 | <example> | |
840 | <title>Download a Fedora image and start a shell in it</title> | |
841 | ||
842 | <programlisting># machinectl pull-raw --verify=no http://ftp.halifax.rwth-aachen.de/fedora/linux/releases/21/Cloud/Images/x86_64/Fedora-Cloud-Base-20141203-21.x86_64.raw.xz | |
e0ea94c1 LP |
843 | # systemd-nspawn -M Fedora-Cloud-Base-20141203-21</programlisting> |
844 | ||
798d3a52 ZJS |
845 | <para>This downloads an image using |
846 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
847 | and opens a shell in it.</para> | |
848 | </example> | |
e0ea94c1 | 849 | |
798d3a52 ZJS |
850 | <example> |
851 | <title>Build and boot a minimal Fedora distribution in a container</title> | |
8f7a3c14 | 852 | |
09c76ef6 | 853 | <programlisting># dnf -y --releasever=23 --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora --enablerepo=updates install systemd passwd dnf fedora-release vim-minimal |
2b3987a8 | 854 | # systemd-nspawn -bD /srv/mycontainer</programlisting> |
8f7a3c14 | 855 | |
798d3a52 ZJS |
856 | <para>This installs a minimal Fedora distribution into the |
857 | directory <filename noindex='true'>/srv/mycontainer/</filename> | |
858 | and then boots an OS in a namespace container in it.</para> | |
859 | </example> | |
8f7a3c14 | 860 | |
798d3a52 ZJS |
861 | <example> |
862 | <title>Spawn a shell in a container of a minimal Debian unstable distribution</title> | |
8f7a3c14 | 863 | |
798d3a52 | 864 | <programlisting># debootstrap --arch=amd64 unstable ~/debian-tree/ |
25f5971b | 865 | # systemd-nspawn -D ~/debian-tree/</programlisting> |
8f7a3c14 | 866 | |
798d3a52 ZJS |
867 | <para>This installs a minimal Debian unstable distribution into |
868 | the directory <filename>~/debian-tree/</filename> and then | |
869 | spawns a shell in a namespace container in it.</para> | |
870 | </example> | |
8f7a3c14 | 871 | |
798d3a52 ZJS |
872 | <example> |
873 | <title>Boot a minimal Arch Linux distribution in a container</title> | |
68562936 | 874 | |
798d3a52 | 875 | <programlisting># pacstrap -c -d ~/arch-tree/ base |
68562936 WG |
876 | # systemd-nspawn -bD ~/arch-tree/</programlisting> |
877 | ||
ff9b60f3 | 878 | <para>This installs a minimal Arch Linux distribution into the |
798d3a52 ZJS |
879 | directory <filename>~/arch-tree/</filename> and then boots an OS |
880 | in a namespace container in it.</para> | |
881 | </example> | |
68562936 | 882 | |
798d3a52 ZJS |
883 | <example> |
884 | <title>Boot into an ephemeral <literal>btrfs</literal> snapshot of the host system</title> | |
f9f4dd51 | 885 | |
798d3a52 | 886 | <programlisting># systemd-nspawn -D / -xb</programlisting> |
f9f4dd51 | 887 | |
798d3a52 ZJS |
888 | <para>This runs a copy of the host system in a |
889 | <literal>btrfs</literal> snapshot which is removed immediately | |
890 | when the container exits. All file system changes made during | |
891 | runtime will be lost on shutdown, hence.</para> | |
892 | </example> | |
f9f4dd51 | 893 | |
798d3a52 ZJS |
894 | <example> |
895 | <title>Run a container with SELinux sandbox security contexts</title> | |
a8828ed9 | 896 | |
798d3a52 | 897 | <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container |
a8828ed9 | 898 | # systemd-nspawn -L system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -Z system_u:system_r:svirt_lxc_net_t:s0:c0,c1 -D /srv/container /bin/sh</programlisting> |
798d3a52 ZJS |
899 | </example> |
900 | </refsect1> | |
901 | ||
902 | <refsect1> | |
903 | <title>Exit status</title> | |
904 | ||
905 | <para>The exit code of the program executed in the container is | |
906 | returned.</para> | |
907 | </refsect1> | |
908 | ||
909 | <refsect1> | |
910 | <title>See Also</title> | |
911 | <para> | |
912 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
f757855e | 913 | <citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
798d3a52 ZJS |
914 | <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
915 | <citerefentry project='mankier'><refentrytitle>dnf</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
798d3a52 ZJS |
916 | <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
917 | <citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
918 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
919 | <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
3ba3a79d | 920 | <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
798d3a52 ZJS |
921 | </para> |
922 | </refsect1> | |
8f7a3c14 LP |
923 | |
924 | </refentry> |