Dynamic multipathing support is available for Fibre Channel and iSCSI storage arrays (round robin is default balancing mode). XenServer also supports the LSI Multi-Path Proxy Driver (MPP) for the Redundant Disk Array Controller (RDAC) - by default this driver is disabled. Multipathing to SAS based SANs is not enabled, changes must typically be made to XenServer as SAS drives do not readily appear as emulated SCSI LUNs.