Compaq Infortrend Grouping Hard Drives and LUN Mapping, Dedicated Communications Loops - “RCC”

The basic configuration rules are:

1.All channels should be connected to both controllers as diagrammed above.

2.To reduce the chance of downtime, more than one hub or switch can be used to connect to host computer for path redundancy.

3.For the Fibre-to-Fibre controllers or RAID systems, there are two options with configuring the communications loops between controllers:

1). Dedicated Communications Loops – “RCC”

The first option is choosing one or two Fibre loops as the dedicated communications paths. Two for communications is recommended for the path redundancy it provides.

Using two channels for the communications offers a greater throughput and hence a better performance.

2). Communications over Drive Loops – “Drive + RCC”

Configure all drive loops into the “Drive + RCC” mode to let them share the communications traffic. The controllers can automatically distribute the communications traffic across all drive loops.

Workflow is balanced among loops. Using the drive/RCC mode allows more channels to be used for drive connection. With a 6- channel controller, for instance, there can be as many as two channels for host and four channels for drive (drive + RCC). All channels are used for IO traffic while the system is still benefited from controller communications.

10.1.3 Grouping Hard Drives and LUN Mapping

Listed below are the array settings that need to be considered when configuring a dual-controller system:

1.How many logical drives, logical volumes, or logical partitions, and in what sizes?

2.System drive mapping (primary/secondary ID): how many storage volumes will appear to which host port? and managed by which controller?

10-4 Infortrend