table of contents
- bookworm 252.30-1~deb12u2
- bookworm-backports 254.16-1~bpo12+1
VERITYTAB(5) | veritytab | VERITYTAB(5) |
NAME¶
veritytab - Configuration for verity block devices
SYNOPSIS¶
/etc/veritytab
DESCRIPTION¶
The /etc/veritytab file describes verity protected block devices that are set up during system boot.
Empty lines and lines starting with the "#" character are ignored. Each of the remaining lines describes one verity protected block device. Fields are delimited by white space.
Each line is in the form
volume-name data-device hash-device roothash [options]
The first four fields are mandatory, the remaining one is optional.
The first field contains the name of the resulting verity volume; its block device is set up below /dev/mapper/.
The second field contains a path to the underlying block data device, or a specification of a block device via UUID= followed by the UUID.
The third field contains a path to the underlying block hash device, or a specification of a block device via UUID= followed by the UUID.
The fourth field is the roothash in hexadecimal.
The fifth field, if present, is a comma-delimited list of options. The following options are recognized:
superblock=BOOL
Added in version 254.
format=NUMBER
Added in version 254.
data-block-size=BYTES
Added in version 254.
hash-block-size=BYTES
Added in version 254.
data-blocks=BLOCKS
Added in version 254.
hash-offset=BYTES
Added in version 254.
salt=HEX
Added in version 254.
uuid=UUID
Added in version 254.
ignore-corruption, restart-on-corruption, panic-on-corruption
Added in version 248.
ignore-zero-blocks
Warning
Use this option only in very specific cases. This option is available since Linux kernel version 4.5.
check-at-most-once
Warning
It provides a reduced level of security because only offline tampering of the data device's content will be detected, not online tampering. This option is available since Linux kernel version 4.17.
hash=HASH
Added in version 254.
fec-device=PATH
Added in version 254.
fec-offset=BYTES
Added in version 254.
fec-roots=NUM
Added in version 254.
root-hash-signature=PATH|base64:HEX
Added in version 248.
_netdev
Hint: if this device is used for a mount point that is specified in fstab(5), the _netdev option should also be used for the mount point. Otherwise, a dependency loop might be created where the mount point will be pulled in by local-fs.target, while the service to configure the network is usually only started after the local file system has been mounted.
Added in version 248.
noauto
Added in version 248.
nofail
Added in version 248.
x-initrd.attach
Although it's not necessary to mark the mount entry for the root file system with x-initrd.mount, x-initrd.attach is still recommended with the verity protected block device containing the root file system as otherwise systemd will attempt to detach the device during the regular system shutdown while it's still in use. With this option the device will still be detached but later after the root file system is unmounted.
All other verity protected block devices that contain file systems mounted in the initrd should use this option.
Added in version 248.
At early boot and when the system manager configuration is reloaded, this file is translated into native systemd units by systemd-veritysetup-generator(8).
EXAMPLES¶
Example 1. /etc/veritytab example
Set up two verity protected block devices. One using device blocks, another using files.
usr PARTUUID=783e45ae-7aa3-484a-beef-a80ff9c19cbb PARTUUID=21dc1dfe-4c33-8b48-98a9-918a22eb3e37 36e3f740ad502e2c25e2a23d9c7c17bf0fdad2300b7580842d4b7ec1fb0fa263 auto data /etc/data /etc/hash a5ee4b42f70ae1f46a08a7c92c2e0a20672ad2f514792730f5d49d7606ab8fdf auto
SEE ALSO¶
systemd(1), systemd-veritysetup@.service(8), systemd-veritysetup-generator(8), fstab(5), veritysetup(8)
systemd 256 |