Dell PowerVault ME4 Series Storage System Administrator’s Guide

About initiators, hosts, and host groups

An initiator represents an external port to which the storage system is connected. The external port may be a port in an I/O adapter such as an FC HBA in a server.

The controllers automatically discover initiators that have sent an inquiry command or a report luns command to the storage system, which typically happens when a host boots up or rescans for devices. When the command is received, the system saves the initiator ID. You can also manually create entries for initiators. For example, you might want to define an initiator before a controller port is physically connected through a switch to a host.

You can assign a nickname to an initiator to make it easy to recognize for volume mapping. For a named initiator, you can also select a profile specific to the operating system for that initiator. A maximum of 512 names can be assigned.

For ease of management, you can group 1 to 128 initiators that represent a server into a host. You can also group 1 to 256 hosts into a host group. This fact enables you to perform mapping operations for all initiators in a host, or all initiators and hosts in a group, instead of for each initiator or host individually. An initiator must have a nickname to be added to a host, and an initiator can be a member of only one host. A host can be a member of only one group. A host cannot have the same name as another host, but can have the same name as any initiator. A host group cannot have the same name as another host group, but can have the same name as any host. A maximum of 32 host groups can exist.

If it becomes necessary to add more hosts after CHAP is enabled, additional CHAP node names and secrets can be added. If a host attempts to log in to the storage system, it will become visible to the system, even if the full login is not successful due to incompatible CHAP definitions. This information may be useful in configuring CHAP entries for new hosts. This information becomes visible when an iSCSI discovery session is established, because the storage system does not require discovery sessions to be authenticated. CHAP authentication must succeed for normal sessions to move to the full feature phase.