Mirror target

modulename: dm-mirror.ko

configname: CONFIG_DM_MIRROR

Linux Kernel Configuration
└─>Device Drivers
└─>Multiple devices driver support (RAID and LVM)
└─>Mirror target
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Allow volume managers to mirror logical volumes, also
needed for live data migration tools such as 'pvmove'.

source code: