1INTEGRITYTAB(5) integritytab INTEGRITYTAB(5)
2
3
4
6 integritytab - Configuration for integrity block devices
7
9 /etc/integritytab
10
12 The /etc/integritytab file describes integrity protected block devices
13 that are set up during system boot.
14
15 Empty lines and lines starting with the "#" character are ignored. Each
16 of the remaining lines describes one verity integrity protected block
17 device. Fields are delimited by white space.
18
19 Each line is in the form
20
21 volume-name block-device
22 [keyfile|-] [options|-]
23
24 The first two fields are mandatory, the remaining two are optional and
25 only required if user specified non-default options during integrity
26 format.
27
28 The first field contains the name of the resulting integrity volume;
29 its block device is set up below /dev/mapper/.
30
31 The second field contains a path to the underlying block device, or a
32 specification of a block device via "UUID=" followed by the UUID,
33 "PARTUUID=" followed by the partition UUID, "LABEL=" followed by the
34 label, "PARTLABEL=" followed by the partition label.
35
36 The third field if present contains an absolute filename path to a key
37 file or a "-" to specify none. When the filename is present, the
38 "integrity-algorithm" defaults to "hmac-sha256" with the key length
39 derived from the number of bytes in the key file. At this time the only
40 supported integrity algorithm when using key file is hmac-sha256. The
41 maximum size of the key file is 4096 bytes.
42
43 The fourth field, if present, is a comma-delimited list of options or a
44 "-" to specify none. The following options are recognized:
45
46 allow-discards
47 Allow the use of discard (TRIM) requests for the device. This
48 option is available since the Linux kernel version 5.7.
49
50 journal-watermark=[0..100]%
51 Journal watermark in percent. When the journal percentage exceeds
52 this watermark, the journal flush will be started. Setting a value
53 of "0%" uses default value.
54
55 journal-commit-time=[0..N]
56 Commit time in milliseconds. When this time passes (and no explicit
57 flush operation was issued), the journal is written. Setting a
58 value of zero uses default value.
59
60 data-device=/dev/disk/by-...
61 Specify a separate block device that contains existing data. The
62 second field specified in the integritytab for block device then
63 will contain calculated integrity tags and journal for data-device,
64 but not the end user data.
65
66 integrity-algorithm=[crc32c|crc32|sha1|sha256|hmac-sha256]
67 The algorithm used for integrity checking. The default is crc32c.
68 Must match option used during format.
69
70 At early boot and when the system manager configuration is reloaded,
71 this file is translated into native systemd units by systemd-
72 integritysetup-generator(8).
73
75 Example 1. /etc/integritytab
76
77 Set up two integrity protected block devices.
78
79 home PARTUUID=4973d0b8-1b15-c449-96ec-94bab7f6a7b8 - journal-commit-time=10,allow-discards,journal-watermark=55%
80 data PARTUUID=5d4b1808-be76-774d-88af-03c4c3a41761 - allow-discards
81
82 Example 2. /etc/integritytab
83
84 Set up 1 integrity protected block device using defaults
85
86 home PARTUUID=4973d0b8-1b15-c449-96ec-94bab7f6a7b8
87
88 Example 3. /etc/integritytab
89
90 Set up 1 integrity device using existing data block device which
91 contains user data
92
93 home PARTUUID=4973d0b8-1b15-c449-96ec-94bab7f6a7b8 - data-device=/dev/disk/by-uuid/9276d9c0-d4e3-4297-b4ff-3307cd0d092f
94
95 Example 4. /etc/integritytab
96
97 Set up 1 integrity device using a HMAC key file using defaults
98
99 home PARTUUID=4973d0b8-1b15-c449-96ec-94bab7f6a7b8 /etc/hmac.key
100
102 systemd(1), systemd-integritysetup@.service(8), systemd-integritysetup-
103 generator(8), integritysetup(8),
104
105
106
107systemd 251 INTEGRITYTAB(5)