Zero target

modulename: dm-zero.ko

configname: CONFIG_DM_ZERO

Linux Kernel Configuration
└─>Device Drivers
└─>Multiple devices driver support (RAID and LVM)
└─>Zero target
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
A target that discards writes, and returns all zeroes for
reads. Useful in some recovery situations.

source code:
drivers/md/dm-zero.c