If one controller fails, the other one will immediately take over to provide high availability with the least downtime.

Specification

Product
Product id	593357
Brand	QNAP
Partnr	CTL-ES1640DC-V2-80G
EAN/UPC code	4713213511374
Warranty (months)	36 months
Technical details
Mac compatibility	N
Supported hard disk drive interfaces	SAS