Dot Hill Systems II 200 FC Fibre Channel Architecture, Redundant Configuration Considerations

1.5Fibre Channel Architecture

Each RAID array has six Fibre Channels with the following defaults:

■Channels 0, 1, 4, and 5 are host channels connected to servers. Any SANnet II 200 FC array host channels can be reassigned as drive channels to connect to expansion units. SANnet II 200 SATA array channels 3 and 4 can also be reassigned as drive channels.

■Channels 2 and 3 are dedicated drive channels that connect the internal 12-disk drives in the RAID chassis, and can also be used to add expansion units to the configuration.

Note – SANnet II 200 SATA SE devices do not support expansion units. Use the SANnet II 200 SATA device if your array requires expansion units.

■FC-AL is the default mode. Point-to-point is also available.

The SANnet II 200 FC expansion unit has a total of four FC-AL ports. The SANnet II 200 SATA expansion unit has a total of eight FC-AL ports. The SANnet II 200 SATA SE has a total of six FC-AL ports.

Note – Throughout this manual, Fibre Channel-Arbitrated Loops are referred to simply as loops.

1.5.1Redundant Configuration Considerations

This section provides information about setting up redundant configurations for increased reliability. For more detailed information about configuration requirements, refer to the SANnet II 200 FC and SATA Array Best Practices Manual.

1.5.1.1Host Bus Adapters

Fibre Channel is widely applied to storage configurations with topologies that aim to avoid loss of data due to component failure. As a rule, the connections between source and target should be configured in redundant pairs.

The recommended host-side connection consists of two or more host bus adapters (HBAs). Each HBA is used to configure a Fibre Channel loop between the host computer and the array.

1-14SANnet II 200 FC, SATA, and SATA SE Array Installation, Operation, and Service Manual • March 2005