RAID 1 over TCP/IP for Linux (user documentation)

 Drbd is a block device which is designed to build high availability
 clusters by providing a virtual shared device which keeps disks in
 nodes synchronised using TCP/IP. This simulates RAID 1 but avoiding
 the use of uncommon hardware (shared SCSI buses or Fibre Channel).
 It is currently limited to fail-over HA clusters.
 .
 This package contains the DRBD User's Guide in HTML and PDF format.