Compaq Storage

分享我的技巧 : MA6000 Multiple-bus failover


分享我的技巧 : MA6000 Multiple-bus failover

Multiple-Bus Failover configuration

Multiple-bus failover is host assisted. It requires a dual-redundant configuration in which each controller has its own bus connection to the host. If one host connection is lost, the host can access storage through the other connection. It requires operating system software to function.

In multiple-bus failover mode, all ports on both controllers are active and have the ability to present all logical units to the host. The host distributes the I/O load between the controllers.

Multiple-bus failover occurs when the host driver discovers that it cannot communicate over a particular path to its logical units. Once this condition is detected, the host drivers and the controllers immediately coordinate moving the I/O stream to another path.

The failover occurs from one controller to the other controller, port 1 to port 1, and port 2 to port 2.

The host must have two Fibre Channel host bus adapters (HBA) as well as operating system software to support this configuration.

Example of Multiple-Bus Failover

Mulitiple-bus failover is used when highest availability and highest performance are needed. It provides:

A no single point of failure (NSPOF) configuration.

Higher availability than dual-redundant controllers in transparent failover mode.