D-Link DSN-5210-10 - xStack Storage Area Network Array Hard Drive Hardware Reference Manual page 15

A DSN-5110-10 with dual controllers (an additional controller DSN-510 is inserted in the second bay),
a DSN-5210-10 with dual controllers (an additional controller DSN-520 is inserted in the second bay)
or a DSN-5410-10 with dual controllers (an additional controller DSN-540 is inserted in the second
bay) will require a DSN-5000-10 expansion array with two I/O modules (an additional I/O module
DSN-500 is inserted in the second bay of the DSN-5000-10). An additional SAS to mini-SAS cable
(provided with the DSN-500) will connect the second controller in the DSN-5110-10, DSN-5210-10 or
DSN-5410-10 to the second I/O module (DSN-500) installed in the DSN-5000-10 expansion array. You
will now have dual redundancy between the DSN-5110-10, DSN-5210-10 or DSN-5410-10 and the DSN-
5000-10 expansion array.
DSN-5000 series Hardware Reference Guide 7