EMC CLARiiON storage systems work with ESXi hosts in iSCSI SAN configurations. Generally, you use the EMC software to perform configurations.
This is an active-passive disk array, so any related issues that apply to all active-passive disk arrays are relevant. In addition, keep in mind the following:
To avoid the possibility of path thrashing, the default multipathing policy is Most Recently Used, not Fixed. The ESXi system sets the default policy when it identifies the storage system.
To boot from a SAN, choose the active storage processor for the boot LUN’s target in the HBA BIOS.
For ESXi to support EMC CLARiiON with ALUA, check the HCLs to make sure that you use the correct firmware version on the storage array. For additional information, contact your storage vendor.
Certain EMC CLARiiON CX3 models might not behave appropriately during periods of network congestion. For information on how to address this behavior, see the VMware knowledge base article at http://kb.vmware.com/kb/1002598.