Device mapper

It forms the foundation of the logical volume manager (LVM), software RAIDs and dm-crypt disk encryption, and offers additional features such as file system snapshots.

Data can be also modified in transition, which is performed, for example, in the case of device mapper providing disk encryption or simulation of unreliable hardware behavior.

[7] Functions provided by the device mapper include linear, striped and error mappings, as well as crypt and multipath targets.

As another example, crypt target encrypts the data passing through the specified device, by using the Linux kernel's Crypto API.

[1] As of 2014[update], the following mapping targets are available:[1][5] Linux kernel features and projects built on top of the device mapper include the following:

The position of the device mapper targets within various layers of the Linux kernel 's storage stack. [ 8 ]