vsphere-esxi-vcenter-server-55-storage-guide

vSphere StorageFigure 23‐1. Multipathing and Failover with Fibre ChannelHost 1 Host 2HBA2 HBA1 HBA3 HBA4switchswitchSP1SP2storage arraySimilarly, if SP1 fails or the links between SP1 and the switches breaks, SP2 takes over and provides theconnection between the switch and the storage device. This process is called SP failover. VMware ESXisupports both HBA and SP failovers with its multipathing capability.Host-Based Failover with iSCSIWhen setting up your ESXi host for multipathing and failover, you can use multiple iSCSI HBAs or multipleNICs depending on the type of iSCSI adapters on your host.For information on different types of iSCSI adapters, see “iSCSI Initiators,” on page 71.When you use multipathing, specific considerations apply.• ESXi does not support multipathing when you combine an independent hardware adapter withsoftware iSCSI or dependent iSCSI adapters in the same host.• Multipathing between software and dependent adapters within the same host is supported.• On different hosts, you can mix both dependent and independent adapters.The following illustration shows multipathing setups possible with different types of iSCSI initiators.216 VMware, Inc.