What is DRBD (Distributed Replicated Block Device)? DRBD (Distributed Replicated Block Device) is a Linux-based software component to mirror or replicate individual storage devices (such as hard disks or partitions) from one node to the other(s) over a network connection. DRBD makes it possible to maintain consistency of data among multiple systems in a network. DRBD also ensures high availability (HA) for Linux applications. DRBD supports three distinct replication modes, allowing three degrees of replication synchronicity.