1CRYPTSETUP-FVAULT2DUMP(8) Maintenance Commands CRYPTSETUP-FVAULT2DUMP(8)
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6 cryptsetup-fvault2Dump - dump the header information of a FVAULT2
7 (FileVault2 compatible) device
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10 cryptsetup fvault2Dump [<options>] <device>
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13 Dump the header information of a FVAULT2 (FileVault2 compatible)
14 device.
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16 If the --dump-volume-key option is used, the FVAULT2 device volume key
17 is dumped instead of header information. You have to provide password
18 or keyfile to dump volume key.
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20 Beware that the volume key can be used to decrypt the data stored in
21 the container without a passphrase. This means that if the volume key
22 is compromised, the whole device has to be erased to prevent further
23 access. Use this option carefully.
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25 <options> can be [--dump-volume-key, --volume-key-file, --key-file,
26 --keyfile-offset, --keyfile-size, --timeout].
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29 --key-file, -d name
30 Read the passphrase from file.
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32 If the name given is "-", then the passphrase will be read from
33 stdin. In this case, reading will not stop at newline characters.
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35 See section NOTES ON PASSPHRASE PROCESSING in cryptsetup(8) for
36 more information.
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38 --keyfile-offset value
39 Skip value bytes at the beginning of the key file.
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41 --keyfile-size, -l value
42 Read a maximum of value bytes from the key file. The default is to
43 read the whole file up to the compiled-in maximum that can be
44 queried with --help. Supplying more data than the compiled-in
45 maximum aborts the operation.
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47 This option is useful to cut trailing newlines, for example. If
48 --keyfile-offset is also given, the size count starts after the
49 offset.
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51 --volume-key-file, --master-key-file (OBSOLETE alias)
52 Use a volume key stored in a file. The volume key is stored in a
53 file instead of being printed out to standard output.
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55 --dump-volume-key, --dump-master-key (OBSOLETE alias)
56 Print the volume key in the displayed information. Use with care,
57 as the volume key can be used to bypass the passphrases, see also
58 option --volume-key-file.
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60 --timeout, -t <number of seconds>
61 The number of seconds to wait before timeout on passphrase input
62 via terminal. It is relevant every time a passphrase is asked. It
63 has no effect if used in conjunction with --key-file.
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65 This option is useful when the system should not stall if the user
66 does not input a passphrase, e.g. during boot. The default is a
67 value of 0 seconds, which means to wait forever.
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69 --batch-mode, -q
70 Suppresses all confirmation questions. Use with care!
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72 If the --verify-passphrase option is not specified, this option
73 also switches off the passphrase verification.
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75 --debug or --debug-json
76 Run in debug mode with full diagnostic logs. Debug output lines are
77 always prefixed by #.
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79 If --debug-json is used, additional LUKS2 JSON data structures are
80 printed.
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82 --version, -V
83 Show the program version.
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85 --usage
86 Show short option help.
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88 --help, -?
89 Show help text and default parameters.
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92 Report bugs at cryptsetup mailing list <cryptsetup@lists.linux.dev> or
93 in Issues project section
94 <https://gitlab.com/cryptsetup/cryptsetup/-/issues/new>.
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96 Please attach output of the failed command with --debug option added.
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99 Cryptsetup FAQ
100 <https://gitlab.com/cryptsetup/cryptsetup/wikis/FrequentlyAskedQuestions>
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102 cryptsetup(8), integritysetup(8) and veritysetup(8)
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105 Part of cryptsetup project <https://gitlab.com/cryptsetup/cryptsetup/>.
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109cryptsetup 2.6.1 2023-02-10 CRYPTSETUP-FVAULT2DUMP(8)