man/crypttab.xml

   1 <?xml version="1.0"?>
   2 <!--*-nxml-*-->
   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   4   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   This is based on crypttab(5) from Fedora's initscripts package, which in
   9   turn is based on Debian's version.
  10
  11   The Red Hat version has been written by Miloslav Trmac <mitr@redhat.com>.
  12 -->
  13 <refentry id="crypttab" conditional='HAVE_LIBCRYPTSETUP' xmlns:xi="http://www.w3.org/2001/XInclude">
  14
  15   <refentryinfo>
  16     <title>crypttab</title>
  17     <productname>systemd</productname>
  18   </refentryinfo>
  19
  20   <refmeta>
  21     <refentrytitle>crypttab</refentrytitle>
  22     <manvolnum>5</manvolnum>
  23   </refmeta>
  24
  25   <refnamediv>
  26     <refname>crypttab</refname>
  27     <refpurpose>Configuration for encrypted block devices</refpurpose>
  28   </refnamediv>
  29
  30   <refsynopsisdiv>
  31     <para><filename>/etc/crypttab</filename></para>
  32   </refsynopsisdiv>
  33
  34   <refsect1>
  35     <title>Description</title>
  36
  37     <para>The <filename>/etc/crypttab</filename> file describes
  38     encrypted block devices that are set up during system boot.</para>
  39
  40     <para>Empty lines and lines starting with the <literal>#</literal>
  41     character are ignored. Each of the remaining lines describes one
  42     encrypted block device. Fields are delimited by white space.</para>
  43
  44     <para>Each line is in the form<programlisting><replaceable>volume-name</replaceable> <replaceable>encrypted-device</replaceable> <replaceable>key-file</replaceable> <replaceable>options</replaceable></programlisting>
  45     The first two fields are mandatory, the remaining two are
  46     optional.</para>
  47
  48     <para>Setting up encrypted block devices using this file supports
  49     three encryption modes: LUKS, TrueCrypt and plain. See
  50     <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  51     for more information about each mode. When no mode is specified in
  52     the options field and the block device contains a LUKS signature,
  53     it is opened as a LUKS device; otherwise, it is assumed to be in
  54     raw dm-crypt (plain mode) format.</para>
  55
  56     <para>The first field contains the name of the resulting encrypted volume; its block device is set up
  57     below <filename>/dev/mapper/</filename>.</para>
  58
  59     <para>The second field contains a path to the underlying block
  60     device or file, or a specification of a block device via
  61     <literal>UUID=</literal> followed by the UUID.</para>
  62
  63     <para>The third field specifies an absolute path to a file to read the encryption key from. Optionally,
  64     the path may be followed by <literal>:</literal> and an fstab device specification (e.g. starting with
  65     <literal>LABEL=</literal> or similar); in which case, the path is relative to the device file system
  66     root. If the field is not present or set to <literal>none</literal> or <literal>-</literal>, a key file
  67     named after the volume to unlock (i.e. the first column of the line), suffixed with
  68     <filename>.key</filename> is automatically loaded from the <filename>/etc/cryptsetup-keys.d/</filename>
  69     and <filename>/run/cryptsetup-keys.d/</filename> directories, if present. Otherwise, the password has to
  70     be manually entered during system boot. For swap encryption, <filename>/dev/urandom</filename> may be
  71     used as key file.</para>
  72
  73     <para>The fourth field, if present, is a comma-delimited list of
  74     options. The following options are recognized:</para>
  75
  76     <variablelist class='fstab-options'>
  77
  78       <varlistentry>
  79         <term><option>cipher=</option></term>
  80
  81         <listitem><para>Specifies the cipher to use. See
  82         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  83         for possible values and the default value of this option. A
  84         cipher with unpredictable IV values, such as
  85         <literal>aes-cbc-essiv:sha256</literal>, is
  86         recommended.</para></listitem>
  87       </varlistentry>
  88
  89       <varlistentry>
  90         <term><option>discard</option></term>
  91
  92         <listitem><para>Allow discard requests to be passed through the encrypted block
  93         device. This improves performance on SSD storage but has security implications.
  94         </para></listitem>
  95       </varlistentry>
  96
  97       <varlistentry>
  98         <term><option>hash=</option></term>
  99
 100         <listitem><para>Specifies the hash to use for password
 101         hashing. See
 102         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 103         for possible values and the default value of this
 104         option.</para></listitem>
 105       </varlistentry>
 106
 107       <varlistentry>
 108         <term><option>header=</option></term>
 109
 110         <listitem><para>Use a detached (separated) metadata device or
 111         file where the LUKS header is stored. This option is only
 112         relevant for LUKS devices. See
 113         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 114         for possible values and the default value of this
 115         option.</para></listitem>
 116       </varlistentry>
 117
 118       <varlistentry>
 119         <term><option>keyfile-offset=</option></term>
 120
 121         <listitem><para>Specifies the number of bytes to skip at the
 122         start of the key file. See
 123         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 124         for possible values and the default value of this
 125         option.</para></listitem>
 126       </varlistentry>
 127
 128       <varlistentry>
 129         <term><option>keyfile-size=</option></term>
 130
 131         <listitem><para>Specifies the maximum number of bytes to read
 132         from the key file. See
 133         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 134         for possible values and the default value of this option. This
 135         option is ignored in plain encryption mode, as the key file
 136         size is then given by the key size.</para></listitem>
 137       </varlistentry>
 138
 139       <varlistentry>
 140         <term><option>keyfile-erase</option></term>
 141
 142         <listitem><para>If enabled, the specified key file is erased after the volume is activated or when
 143         activation fails. This is in particular useful when the key file is only acquired transiently before
 144         activation (e.g. via a file in <filename>/run/</filename>, generated by a service running before
 145         activation), and shall be removed after use. Defaults to off.</para></listitem>
 146       </varlistentry>
 147
 148       <varlistentry>
 149         <term><option>key-slot=</option></term>
 150
 151         <listitem><para>Specifies the key slot to compare the
 152         passphrase or key against. If the key slot does not match the
 153         given passphrase or key, but another would, the setup of the
 154         device will fail regardless. This option implies
 155         <option>luks</option>. See
 156         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 157         for possible values. The default is to try all key slots in
 158         sequential order.</para></listitem>
 159       </varlistentry>
 160
 161       <varlistentry>
 162         <term><option>keyfile-timeout=</option></term>
 163
 164         <listitem><para> Specifies the timeout for the device on
 165         which the key file resides and falls back to a password if
 166         it could not be mounted. See
 167         <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 168         for key files on external devices.
 169         </para></listitem>
 170       </varlistentry>
 171
 172       <varlistentry>
 173         <term><option>luks</option></term>
 174
 175         <listitem><para>Force LUKS mode. When this mode is used, the
 176         following options are ignored since they are provided by the
 177         LUKS header on the device: <option>cipher=</option>,
 178         <option>hash=</option>,
 179         <option>size=</option>.</para></listitem>
 180       </varlistentry>
 181
 182       <varlistentry>
 183         <term><option>bitlk</option></term>
 184
 185         <listitem><para>Decrypt Bitlocker drive. Encryption parameters
 186         are deduced by cryptsetup from Bitlocker header.</para></listitem>
 187       </varlistentry>
 188
 189       <varlistentry>
 190         <term><option>_netdev</option></term>
 191
 192         <listitem><para>Marks this cryptsetup device as requiring network. It will be
 193         started after the network is available, similarly to
 194         <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 195         units marked with <option>_netdev</option>. The service unit to set up this device
 196         will be ordered between <filename>remote-fs-pre.target</filename> and
 197         <filename>remote-cryptsetup.target</filename>, instead of
 198         <filename>cryptsetup-pre.target</filename> and
 199         <filename>cryptsetup.target</filename>.</para>
 200
 201         <para>Hint: if this device is used for a mount point that is specified in
 202         <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 203         the <option>_netdev</option> option should also be used for the mount
 204         point. Otherwise, a dependency loop might be created where the mount point
 205         will be pulled in by <filename>local-fs.target</filename>, while the
 206         service to configure the network is usually only started <emphasis>after</emphasis>
 207         the local file system has been mounted.</para>
 208         </listitem>
 209       </varlistentry>
 210
 211       <varlistentry>
 212         <term><option>noauto</option></term>
 213
 214         <listitem><para>This device will not be added to <filename>cryptsetup.target</filename>.
 215         This means that it will not be automatically unlocked on boot, unless something else pulls
 216         it in. In particular, if the device is used for a mount point, it'll be unlocked
 217         automatically during boot, unless the mount point itself is also disabled with
 218         <option>noauto</option>.</para></listitem>
 219       </varlistentry>
 220
 221       <varlistentry>
 222         <term><option>nofail</option></term>
 223
 224         <listitem><para>This device will not be a hard dependency of
 225         <filename>cryptsetup.target</filename>. It'll still be pulled in and started, but the system
 226         will not wait for the device to show up and be unlocked, and boot will not fail if this is
 227         unsuccessful. Note that other units that depend on the unlocked device may still fail. In
 228         particular, if the device is used for a mount point, the mount point itself also needs to
 229         have the <option>nofail</option> option, or the boot will fail if the device is not unlocked
 230         successfully.</para></listitem>
 231       </varlistentry>
 232
 233       <varlistentry>
 234         <term><option>offset=</option></term>
 235
 236         <listitem><para>Start offset in the backend device, in 512-byte sectors. This
 237         option is only relevant for plain devices.</para></listitem>
 238       </varlistentry>
 239
 240       <varlistentry>
 241         <term><option>plain</option></term>
 242
 243         <listitem><para>Force plain encryption mode.</para></listitem>
 244       </varlistentry>
 245
 246       <varlistentry>
 247         <term><option>read-only</option></term><term><option>readonly</option></term>
 248
 249         <listitem><para>Set up the encrypted block device in read-only
 250         mode.</para></listitem>
 251       </varlistentry>
 252
 253       <varlistentry>
 254         <term><option>same-cpu-crypt</option></term>
 255
 256         <listitem><para>Perform encryption using the same cpu that IO was submitted on. The default is to use
 257         an unbound workqueue so that encryption work is automatically balanced between available CPUs.</para>
 258         <para>This requires kernel 4.0 or newer.</para>
 259         </listitem>
 260       </varlistentry>
 261
 262       <varlistentry>
 263         <term><option>submit-from-crypt-cpus</option></term>
 264
 265         <listitem><para>Disable offloading writes to a separate thread after encryption. There are some
 266         situations where offloading write bios from the encryption threads to a single thread degrades
 267         performance significantly. The default is to offload write bios to the same thread because it benefits
 268         CFQ to have writes submitted using the same context.</para>
 269         <para>This requires kernel 4.0 or newer.</para>
 270         </listitem>
 271       </varlistentry>
 272
 273       <varlistentry>
 274         <term><option>skip=</option></term>
 275
 276         <listitem><para>How many 512-byte sectors of the encrypted data to skip at the
 277         beginning. This is different from the <option>offset=</option> option with respect
 278         to the sector numbers used in initialization vector (IV) calculation. Using
 279         <option>offset=</option> will shift the IV calculation by the same negative
 280         amount. Hence, if <option>offset=<replaceable>n</replaceable></option> is given,
 281         sector <replaceable>n</replaceable> will get a sector number of 0 for the IV
 282         calculation. Using <option>skip=</option> causes sector
 283         <replaceable>n</replaceable> to also be the first sector of the mapped device, but
 284         with its number for IV generation being <replaceable>n</replaceable>.</para>
 285
 286         <para>This option is only relevant for plain devices.</para>
 287         </listitem>
 288       </varlistentry>
 289
 290       <varlistentry>
 291         <term><option>size=</option></term>
 292
 293         <listitem><para>Specifies the key size in bits. See
 294         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 295         for possible values and the default value of this
 296         option.</para></listitem>
 297       </varlistentry>
 298
 299       <varlistentry>
 300         <term><option>sector-size=</option></term>
 301
 302         <listitem><para>Specifies the sector size in bytes. See
 303         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 304         for possible values and the default value of this
 305         option.</para></listitem>
 306       </varlistentry>
 307
 308       <varlistentry>
 309         <term><option>swap</option></term>
 310
 311         <listitem><para>The encrypted block device will be used as a
 312         swap device, and will be formatted accordingly after setting
 313         up the encrypted block device, with
 314         <citerefentry project='man-pages'><refentrytitle>mkswap</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 315         This option implies <option>plain</option>.</para>
 316
 317         <para>WARNING: Using the <option>swap</option> option will
 318         destroy the contents of the named partition during every boot,
 319         so make sure the underlying block device is specified
 320         correctly.</para></listitem>
 321       </varlistentry>
 322
 323       <varlistentry>
 324         <term><option>tcrypt</option></term>
 325
 326         <listitem><para>Use TrueCrypt encryption mode. When this mode
 327         is used, the following options are ignored since they are
 328         provided by the TrueCrypt header on the device or do not
 329         apply:
 330         <option>cipher=</option>,
 331         <option>hash=</option>,
 332         <option>keyfile-offset=</option>,
 333         <option>keyfile-size=</option>,
 334         <option>size=</option>.</para>
 335
 336         <para>When this mode is used, the passphrase is read from the
 337         key file given in the third field. Only the first line of this
 338         file is read, excluding the new line character.</para>
 339
 340         <para>Note that the TrueCrypt format uses both passphrase and
 341         key files to derive a password for the volume. Therefore, the
 342         passphrase and all key files need to be provided. Use
 343         <option>tcrypt-keyfile=</option> to provide the absolute path
 344         to all key files. When using an empty passphrase in
 345         combination with one or more key files, use
 346         <literal>/dev/null</literal> as the password file in the third
 347         field.</para></listitem>
 348       </varlistentry>
 349
 350       <varlistentry>
 351         <term><option>tcrypt-hidden</option></term>
 352
 353         <listitem><para>Use the hidden TrueCrypt volume. This option
 354         implies <option>tcrypt</option>.</para>
 355
 356         <para>This will map the hidden volume that is inside of the
 357         volume provided in the second field. Please note that there is
 358         no protection for the hidden volume if the outer volume is
 359         mounted instead. See
 360         <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 361         for more information on this limitation.</para></listitem>
 362       </varlistentry>
 363
 364       <varlistentry>
 365         <term><option>tcrypt-keyfile=</option></term>
 366
 367         <listitem><para>Specifies the absolute path to a key file to
 368         use for a TrueCrypt volume. This implies
 369         <option>tcrypt</option> and can be used more than once to
 370         provide several key files.</para>
 371
 372         <para>See the entry for <option>tcrypt</option> on the
 373         behavior of the passphrase and key files when using TrueCrypt
 374         encryption mode.</para></listitem>
 375       </varlistentry>
 376
 377       <varlistentry>
 378         <term><option>tcrypt-system</option></term>
 379
 380         <listitem><para>Use TrueCrypt in system encryption mode. This
 381         option implies <option>tcrypt</option>.</para></listitem>
 382       </varlistentry>
 383
 384       <varlistentry>
 385         <term><option>tcrypt-veracrypt</option></term>
 386
 387         <listitem><para>Check for a VeraCrypt volume.  VeraCrypt is a fork of
 388         TrueCrypt that is mostly compatible, but uses different, stronger key
 389         derivation algorithms that cannot be detected without this flag.
 390         Enabling this option could substantially slow down unlocking, because
 391         VeraCrypt's key derivation takes much longer than TrueCrypt's.  This
 392         option implies <option>tcrypt</option>.</para></listitem>
 393       </varlistentry>
 394
 395       <varlistentry>
 396         <term><option>timeout=</option></term>
 397
 398         <listitem><para>Specifies the timeout for querying for a
 399         password. If no unit is specified, seconds is used. Supported
 400         units are s, ms, us, min, h, d. A timeout of 0 waits
 401         indefinitely (which is the default).</para></listitem>
 402       </varlistentry>
 403
 404       <varlistentry>
 405         <term><option>tmp=</option></term>
 406
 407         <listitem><para>The encrypted block device will be prepared for using it as
 408         <filename>/tmp/</filename>; it will be formatted using <citerefentry
 409         project='man-pages'><refentrytitle>mkfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>. Takes
 410         a file system type as argument, such as <literal>ext4</literal>, <literal>xfs</literal> or
 411         <literal>btrfs</literal>. If no argument is specified defaults to <literal>ext4</literal>. This
 412         option implies <option>plain</option>.</para>
 413
 414         <para>WARNING: Using the <option>tmp</option> option will destroy the contents of the named partition
 415         during every boot, so make sure the underlying block device is specified correctly.</para></listitem>
 416       </varlistentry>
 417
 418       <varlistentry>
 419         <term><option>tries=</option></term>
 420
 421         <listitem><para>Specifies the maximum number of times the user
 422         is queried for a password. The default is 3. If set to 0, the
 423         user is queried for a password indefinitely.</para></listitem>
 424       </varlistentry>
 425
 426       <varlistentry>
 427         <term><option>verify</option></term>
 428
 429         <listitem><para>If the encryption password is read from console, it has to be entered twice to
 430         prevent typos.</para></listitem>
 431       </varlistentry>
 432
 433       <varlistentry>
 434         <term><option>pkcs11-uri=</option></term>
 435
 436         <listitem><para>Takes a <ulink url="https://tools.ietf.org/html/rfc7512">RFC7512 PKCS#11 URI</ulink>
 437         pointing to a private RSA key which is used to decrypt the key specified in the third column of the
 438         line. This is useful for unlocking encrypted volumes through security tokens or smartcards. See below
 439         for an example how to set up this mechanism for unlocking a LUKS volume with a YubiKey security
 440         token. The specified URI can refer directly to a private RSA key stored on a token or alternatively
 441         just to a slot or token, in which case a search for a suitable private RSA key will be performed.  In
 442         this case if multiple suitable objects are found the token is refused. The key configured in the
 443         third column is passed as is to RSA decryption. The resulting decrypted key is then base64 encoded
 444         before it is used to unlock the LUKS volume.</para></listitem>
 445       </varlistentry>
 446
 447       <varlistentry>
 448         <term><option>try-empty-password=</option></term>
 449
 450         <listitem><para>Takes a boolean argument. If enabled, right before asking the user for a password it
 451         is first attempted to unlock the volume with an empty password. This is useful for systems that are
 452         initialized with an encrypted volume with only an empty password set, which shall be replaced with a
 453         suitable password during first boot, but after activation.</para></listitem>
 454       </varlistentry>
 455
 456       <varlistentry>
 457         <term><option>x-systemd.device-timeout=</option></term>
 458
 459         <listitem><para>Specifies how long systemd should wait for a device to show up
 460         before giving up on the entry. The argument is a time in seconds or explicitly
 461         specified units of
 462         <literal>s</literal>,
 463         <literal>min</literal>,
 464         <literal>h</literal>,
 465         <literal>ms</literal>.
 466         </para></listitem>
 467       </varlistentry>
 468
 469       <varlistentry>
 470         <term><option>x-initrd.attach</option></term>
 471
 472         <listitem><para>Setup this encrypted block device in the initramfs, similarly to
 473         <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 474         units marked with <option>x-initrd.mount</option>.</para>
 475
 476         <para>Although it's not necessary to mark the mount entry for the root file system with
 477         <option>x-initrd.mount</option>, <option>x-initrd.attach</option> is still recommended with
 478         the encrypted block device containing the root file system as otherwise systemd will
 479         attempt to detach the device during the regular system shutdown while it's still in
 480         use. With this option the device will still be detached but later after the root file
 481         system is unmounted.</para>
 482
 483         <para>All other encrypted block devices that contain file systems mounted in the initramfs
 484         should use this option.</para>
 485         </listitem>
 486       </varlistentry>
 487
 488     </variablelist>
 489
 490     <para>At early boot and when the system manager configuration is
 491     reloaded, this file is translated into native systemd units by
 492     <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 493   </refsect1>
 494
 495   <refsect1>
 496     <title>Examples</title>
 497     <example>
 498       <title>/etc/crypttab example</title>
 499       <para>Set up four encrypted block devices. One using LUKS for
 500       normal storage, another one for usage as a swap device and two
 501       TrueCrypt volumes.</para>
 502
 503       <programlisting>luks       UUID=2505567a-9e27-4efe-a4d5-15ad146c258b
 504 swap       /dev/sda7       /dev/urandom       swap
 505 truecrypt  /dev/sda2       /etc/container_password  tcrypt
 506 hidden     /mnt/tc_hidden  /dev/null    tcrypt-hidden,tcrypt-keyfile=/etc/keyfile
 507 external   /dev/sda3       keyfile:LABEL=keydev keyfile-timeout=10s</programlisting>
 508     </example>
 509
 510     <example>
 511       <title>Yubikey-based Volume Unlocking Example</title>
 512
 513       <para>The PKCS#11 logic allows hooking up any compatible security token that is capable of storing RSA
 514       decryption keys. Here's an example how to set up a Yubikey security token for this purpose, using
 515       <command>ykman</command> from the yubikey-manager project:</para>
 516
 517 <programlisting><xi:include href="yubikey-crypttab.sh" parse="text" /></programlisting>
 518
 519 <para>A few notes on the above:</para>
 520
 521 <itemizedlist>
 522   <listitem><para>We use RSA (and not ECC), since Yubikeys support PKCS#11 Decrypt() only for RSA keys</para></listitem>
 523   <listitem><para>We use RSA2048, which is the longest key size current Yubikeys support</para></listitem>
 524   <listitem><para>LUKS key size must be shorter than 2048bit due to RSA padding, hence we use 128 bytes</para></listitem>
 525   <listitem><para>We use Yubikey key slot 9d, since that's apparently the keyslot to use for decryption purposes,
 526   <ulink url="https://developers.yubico.com/PIV/Introduction/Certificate_slots.html">see
 527   documentation</ulink>.</para></listitem>
 528 </itemizedlist>
 529
 530     </example>
 531   </refsect1>
 532
 533   <refsect1>
 534     <title>See Also</title>
 535     <para>
 536       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 537       <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 538       <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 539       <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 540       <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 541       <citerefentry project='man-pages'><refentrytitle>mkswap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 542       <citerefentry project='man-pages'><refentrytitle>mke2fs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 543     </para>
 544   </refsect1>
 545
 546 </refentry>