Discovery Sessions

A discovery session is part of the iSCSI protocol. The discovery session returns the set of targets that you can access on an iSCSI storage system.

ESXi systems support dynamic and static discovery.

• Dynamic discovery - Also known as Send Targets discovery. Each time the ESXi host contacts a specified iSCSI storage server, it sends a Send Targets request to the server. In response, the iSCSI storage server supplies a list of available targets to the ESXi host. Monitor and manage with esxcli iscsi adapter discovery sendtarget or vicfg-iscsi commands.
• Static discovery - The ESXi host does not have to perform discovery. Instead, the ESXi host uses the IP addresses or domain names and iSCSI target names, IQN or EUI format names, to communicate with the iSCSI target. Monitor and manage with esxcli iscsi adapter discovery statictarget or vicfg-iscsi commands.

For either case, you set up target discovery addresses so that the initiator can determine which storage resource on the network is available for access. You can do this setup with dynamic discovery or static discovery. With dynamic discovery, all targets associated with an IP address or host name and the iSCSI name are discovered. With static discovery, you must specify the IP address or host name and the iSCSI name of the target you want to access. The iSCSI HBA must be in the same VLAN as both ports of the iSCSI array.