2.4. More than 2-way redundancy

With DRBD 9 it’s possible to have the data stored simultaneously on more than two cluster nodes.

While this has been possible before via stacking, in DRBD 9 this is supported out-of-the-box for (currently) up to 16 nodes. (In practice, using 3-, 4- or perhaps 5-way redundancy via DRBD will make other things the leading cause of downtime.)

The major difference to the stacking solution is that there’s less performance loss, because only one level of data replication is being used.