RAID-1 (mirroring) mode

modulename: raid1.ko

configname: CONFIG_MD_RAID1

Linux Kernel Configuration
└─>Device Drivers
└─>Multi-device support (RAID and LVM)
└─>RAID-1 (mirroring) mode
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
A RAID-1 set consists of several disk drives which are exact copies
of each other. In the event of a mirror failure, the RAID driver
will continue to use the operational mirrors in the set, providing
an error free MD (multiple device) to the higher levels of the
kernel. In a set with N drives, the available space is the capacity
of a single drive, and the set protects against a failure of (N - 1)
drives.

Information about Software RAID on Linux is contained in the
Software-RAID mini-HOWTO, available from
<http://www.tldp.org/docs.html#howto>. There you will also
learn where to get the supporting user space utilities raidtools.

If you want to use such a RAID-1 set, say Y. To compile this code
as a module, choose M here: the module will be called raid1.

If unsure, say Y.

source code: