NAME
veritytab - Configuration for verity block devicesSYNOPSIS
/etc/veritytabDESCRIPTION
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 formvolume-name data-device hash-device roothash options
Defines what to do if a data verity problem is
detected (data corruption). Without these options kernel fails the IO
operation with I/O error. With "--ignore-corruption" option the
corruption is only logged. With "--restart-on-corruption" or
"--panic-on-corruption" the kernel is restarted (panicked)
immediately. (You have to provide way how to avoid restart loops.)
ignore-zero-blocks
Instruct kernel to not verify blocks that are
expected to contain zeroes and always directly return zeroes instead. WARNING:
Use this option only in very specific cases. This option is available since
Linux kernel version 4.5.
check-at-most-once
Instruct kernel to verify blocks only the
first time they are read from the data device, rather than every time.
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.
root-hash-signature=PATH|base64:HEX
A base64 string encoding the root hash
signature prefixed by "base64:" or a path to roothash signature file
used to verify the root hash (in kernel). This feature requires Linux kernel
version 5.4 or more recent.
_netdev
Marks this veritysetup device as requiring
network. It will be started after the network is available, similarly to
systemd.mount(5) units marked with _netdev. The service unit to
set up this device will be ordered between remote-fs-pre.target and
remote-veritysetup.target, instead of veritysetup-pre.target and
veritysetup.target.
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.
noauto
This device will not be added to
veritysetup.target. This means that it will not be automatically enabled on
boot, unless something else pulls it in. In particular, if the device is used
for a mount point, it'll be enabled automatically during boot, unless the
mount point itself is also disabled with noauto.
nofail
This device will not be a hard dependency of
veritysetup.target. It'll still be pulled in and started, but the system will
not wait for the device to show up and be enabled, and boot will not fail if
this is unsuccessful. Note that other units that depend on the enabled device
may still fail. In particular, if the device is used for a mount point, the
mount point itself also needs to have the nofail option, or the boot
will fail if the device is not enabled successfully.
x-initrd.attach
Setup this verity protected block device in
the initrd, similarly to systemd.mount(5) units marked with
x-initrd.mount.
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.
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 252 |