What is Device Mapper?

• Device Mapper is a kernel driver that provides a generic framework for volume management.

• It provides a modular framework for constructing new block devices that map I/O to and from existing devices according to a table of rules.

• It was invented as a replacement for the in-kernel LVM code in 2.4 kernels by Joe Thornber in 2001 shortly after he joined Sistina Software.

• It is included in current 2.6 kernels. A patch is available for 2.4.