- a transparent disk encryption subsystem in [the] Linux kernel... [It is] implemented as a device mapper target and may be stacked on top of other device mapper transformations. It can thus encrypt whole disks (including removable media), partitions, software RAID volumes, logical volumes, as well as files. It appears as a block device, which can be used to back file systems, swap or as an LVM physical volume.
这一部分介绍应用 dm-crypt 来加密整个系统或是某个文件系统挂载点的经典场景。这一部分是作为了解不同实际的加密程序的起点。
查看 /Encrypting an entire system，这个页面教你怎么加密整个系统，特别是加密根分区（root分区）。这里面又有其他细分场景，包括用 LUKS 插件、plain加密模式以及配合LVM使用。
/Device encryption covers how to manually utilize dm-crypt to encrypt a system through the cryptsetup command. It covers examples of the Encryption options with dm-crypt, deals with the creation of keyfiles, LUKS specific commands for key management as well as for Backup and restore.
Swap device encryption
/Swap encryption covers how to add a swap partition to an encrypted system, if required. The swap partition must be encrypted as well to protect any data swapped out by the system. This part details methods without and with suspend-to-disk support.
/Specialties deals with special operations like securing the unencrypted boot partition, using GPG or OpenSSL encrypted keyfiles, a method to boot and unlock via the network, another for setting up discard/TRIM for a SSD, and sections dealing with the encrypt hook and multiple disks.