Consider the following limitations when you zone the IBM
Enterprise Storage Server (ESS) to the system.
To avoid a single point of failure on the IBM ESS, you
must have a minimum of two SAN connections from two separate adapter
bays. The maximum number of IBM ESS SAN connections in the system
switch zone is 16.
Note: The IBM ESS provides ESCON, FICON and Ultra
SCSI connectivity; however, only a 1 or 2 Gb Fibre Channel SAN attachment is supported by the system.