If you want to guarantee the uninterrupted operation of business-critical, you needto build systems in a redundant manner. Server types of redundancy schemes, programmes are varied, redundancy can be a single switch parts, you can also consider using dual-redundant configuration of fiber-optic network, but the cost is very high. But because the two network topology ensures redundancy, so you can use less expensive single power supply switching equipment, even if a switch fails, the host and storage array link switch software will automatically switch to the redundant traffic on the device, until the device to be replaced. If scheduled downtime, maintenance will not affect the company's application, then use a hot-plug redundant power supplies and fan switches, can greatly reduce the cost. Also ensure the power supplies, or fans of any single point of failure does not affect network operation.