Sun Microsystems 280R manual About Multipathing Software

About Multipathing Software

Multipathing software enables you to define and control redundant physical paths to I/O devices such as disk storage arrays and network interfaces. If the active path to a device becomes unavailable, the software automatically switches to an alternate path to maintain availability. This capability is known as automatic failover.

Automatic failover allows a qualifed service provider to remove and replace the faulty component without impacting normal system operations.

To take advantage of multipathing capabilities, your server must be configured with redundant hardware, such as redundant network interfaces or disk drives.

For the Sun Fire 280R system, two different types of multipathing software are available:

■Solaris IP Network Multipathing – Provides multipathing and load-balancing capabilities for IP network interfaces

■VERITAS Volume Manager – Includes a feature called Dynamic Multipathing (DMP) for disk storage arrays

The Solaris implementation of IP Network Multipathing provides the following configurable features:

■Failure detection – The ability to detect when one of a configured group of network adapters fails and to automatically switch (failover) the network access to an alternate adapter in the group.

■Repair detection – The ability to detect when a network adapter that failed previously has been repaired and to automatically switch network access back (failback) to include the repaired adapter.

■Load spreading – The ability to spread network packets across multiple network adapters to achieve higher throughput. Load spreading occurs only when the network traffic is flowing to multiple destinations using multiple connections.

For instructions on how to configure and administer Solaris IP Network Multipathing, consult the IP Network Multipathing Administration Guide provided with your specific Solaris release.

VERITAS Volume Manager software actively supports multiported disk arrays. It automatically recognizes multiple I/O paths to a particular disk device within an array. VERITAS DMP provides increased reliability by providing a path failover mechanism. If one connection to a disk is lost, VERITAS Volume Manager continues

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