1VERITYTAB(5) veritytab VERITYTAB(5)
2
6 veritytab - Configuration for verity block devices
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9 /etc/veritytab
10
12 The /etc/veritytab file describes verity protected block devices that
13 are set up during system boot.
14 Empty lines and lines starting with the "#" character are ignored. Each
16 of the remaining lines describes one verity protected block device.
17 Fields are delimited by white space.
18 Each line is in the form
20 volume-name data-device hash-device roothash options
22 The first four fields are mandatory, the remaining one is optional.
24 The first field contains the name of the resulting verity volume; its
26 block device is set up below /dev/mapper/.
27 The second field contains a path to the underlying block data device,
29 or a specification of a block device via "UUID=" followed by the UUID.
30 The third field contains a path to the underlying block hash device, or
32 a specification of a block device via "UUID=" followed by the UUID.
33 The fourth field is the "roothash" in hexadecimal.
35 The fifth field, if present, is a comma-delimited list of options. The
37 following options are recognized:
38 ignore-corruption, restart-on-corruption, panic-on-corruption
40 Defines what to do if a data verity problem is detected (data
41 corruption). Without these options kernel fails the IO operation
42 with I/O error. With "--ignore-corruption" option the corruption is
43 only logged. With "--restart-on-corruption" or
44 "--panic-on-corruption" the kernel is restarted (panicked)
45 immediately. (You have to provide way how to avoid restart loops.)
46 ignore-zero-blocks
48 Instruct kernel to not verify blocks that are expected to contain
49 zeroes and always directly return zeroes instead. WARNING: Use this
50 option only in very specific cases. This option is available since
51 Linux kernel version 4.5.
52 check-at-most-once
54 Instruct kernel to verify blocks only the first time they are read
55 from the data device, rather than every time. WARNING: It provides
56 a reduced level of security because only offline tampering of the
57 data device's content will be detected, not online tampering. This
58 option is available since Linux kernel version 4.17.
59 root-hash-signature=PATH|base64:HEX
61 A base64 string encoding the root hash signature prefixed by
62 "base64:" or a path to roothash signature file used to verify the
63 root hash (in kernel). This feature requires Linux kernel version
64 5.4 or more recent.
65 _netdev
67 Marks this veritysetup device as requiring network. It will be
68 started after the network is available, similarly to
69 systemd.mount(5) units marked with _netdev. The service unit to set
70 up this device will be ordered between remote-fs-pre.target and
71 remote-veritysetup.target, instead of veritysetup-pre.target and
72 veritysetup.target.
73 Hint: if this device is used for a mount point that is specified in
75 fstab(5), the _netdev option should also be used for the mount
76 point. Otherwise, a dependency loop might be created where the
77 mount point will be pulled in by local-fs.target, while the service
78 to configure the network is usually only started after the local
79 file system has been mounted.
80 noauto
82 This device will not be added to veritysetup.target. This means
83 that it will not be automatically enabled on boot, unless something
84 else pulls it in. In particular, if the device is used for a mount
85 point, it'll be enabled automatically during boot, unless the mount
86 point itself is also disabled with noauto.
87 nofail
89 This device will not be a hard dependency of veritysetup.target.
90 It'll still be pulled in and started, but the system will not wait
91 for the device to show up and be enabled, and boot will not fail if
92 this is unsuccessful. Note that other units that depend on the
93 enabled device may still fail. In particular, if the device is used
94 for a mount point, the mount point itself also needs to have the
95 nofail option, or the boot will fail if the device is not enabled
96 successfully.
97 x-initrd.attach
99 Setup this verity protected block device in the initramfs,
100 similarly to systemd.mount(5) units marked with x-initrd.mount.
101 Although it's not necessary to mark the mount entry for the root
103 file system with x-initrd.mount, x-initrd.attach is still
104 recommended with the verity protected block device containing the
105 root file system as otherwise systemd will attempt to detach the
106 device during the regular system shutdown while it's still in use.
107 With this option the device will still be detached but later after
108 the root file system is unmounted.
109 All other verity protected block devices that contain file systems
111 mounted in the initramfs should use this option.
112 At early boot and when the system manager configuration is reloaded,
114 this file is translated into native systemd units by systemd-
115 veritysetup-generator(8).
116
118 Example 1. /etc/veritytab example
119 Set up two verity protected block devices. One using device blocks,
121 another using files.
122 usr PARTUUID=783e45ae-7aa3-484a-beef-a80ff9c19cbb PARTUUID=21dc1dfe-4c33-8b48-98a9-918a22eb3e37 36e3f740ad502e2c25e2a23d9c7c17bf0fdad2300b7580842d4b7ec1fb0fa263 auto
124 data /etc/data /etc/hash a5ee4b42f70ae1f46a08a7c92c2e0a20672ad2f514792730f5d49d7606ab8fdf auto
125
127 systemd(1), systemd-veritysetup@.service(8), systemd-veritysetup-
128 generator(8), fstab(5), veritysetup(8),
129systemd 251 VERITYTAB(5)