The Exalogic machine name is used to generate host names for network interfaces for all systems. For example, an Exalogic machine name of el01 will result in compute node host names of el01cn01, el01cn02, el01cn03, and so on.
In a multirack configuration, each Exalogic rack name should be unique and identify the rack. Oracle recommends using el01 for the first Exalogic rack, el02 for the second, el03 for the third, and so on.
Note:
You can connect up to eight Exalogic machine full racks, or a combination of 4 Exalogic machine full racks and 4 Oracle Exadata Database Machine full racks together on the same Infiniband fabric, without purchasing additional hardware. To connect more machines, Oracle offers a choice of several high-capacity datacenter switches which allow the creation of Exalogic clouds comprising hundreds of racks and tens of thousands of processors