IBM Z10 BC manual Ficon Support for Cascaded Directors, FCP Channels

The FICON Express4, FICON Express2 and FICON Express channels support native FICON and FICON Channel-to-Channel (CTC) traffi c for attachment to servers, disks, tapes, and printers that comply with the FICON architecture. Native FICON is supported by all of the

z10 BC operating systems. Native FICON and FICON CTC are defi ned as CHPID type FC.

Because the FICON CTC function is included as part of the native FICON (FC) mode of operation, FICON CTC is not limited to intersystem connectivity (as is the case with ESCON), but will support multiple device defi nitions.

FICON Support for Cascaded Directors

Native FICON (FC) channels support cascaded directors. This support is for a single hop confi guration only. Two- director cascading requires a single vendor high integrity fabric. Directors must be from the same vendor since cascaded architecture implementations can be unique. This type of cascaded support is important for disaster recovery and business continuity solutions because it can help provide high availability, extended distance connec- tivity, and (particularly with the implementation of 2 Gb/sec Inter Switch Links) has the potential for fi ber infrastructure cost savings by reducing the number of channels for inter- connecting the two sites.

Two site non-cascaded director topology. Each CEC connects to directors in both sites.

With Inter Switch Links (ISLs), less fiber cabling may be needed for cross-site connectivity

Two Site cascaded director

topology. Each CEC connects to local directors only.

FCP Channels

z10 BC supports FCP channels, switches and FCP/ SCSI disks with full fabric connectivity under Linux on System z and z/VM 5.2 (or later) for Linux as a guest under z/VM, under z/VM 5.2 (or later), and under z/VSE 3.1 for system usage including install and IPL. Support for FCP devices means that z10 BC servers are capable of attaching to select FCP-attached SCSI devices and may access these devices from Linux on z10 BC and z/VSE. This expanded attachability means that enterprises have more choices for new storage solutions, or may have the ability to use existing storage devices, thus leveraging existing invest- ments and lowering total cost of ownership for their Linux implementations.

The same FICON features used for native FICON chan- nels can be defi ned to be used for Fibre Channel Protocol (FCP) channels. FCP channels are defi ned as CHPID type FCP. The 4 Gb/sec capability on the FICON Express4 channel means that 4 Gb/sec link data rates are available for FCP channels as well.

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