Configuring multiple LPARs using the Barr ESCON adapter

The BARR/CHANNEL software with the CHANNEL-IN (ES) adapter supports multiple logical partitions (LPARs). In this example, we will configure three LPARs on one host. To best explain the connections and how they are made, we will start with the SNA gateway configuration and then proceed to the host configuration.

• SNA gateway configuration

• Host configuration

• Summary

SNA gateway configuration

Microsoft SNA Server and HIS are emulation software that provides SNA connectivity to the mainframe. To configure the SNA gateway, you must define the physical connection as well as the type of device that is using the physical connection. A link service describes the hardware device that the SNA gateway uses to attach to the mainframe. A connection describes the type of device connecting through the link service. Common hardware used for link services includes BARR/SYNC for Microsoft Networks for SDLC connections over leased or dial-up lines, DLC (802.2 LLC) connections using Ethernet or Token Ring Network Interface Controllers, and BARR/CHANNEL for direct connections.

Complete the following steps to define the Barr Systems ESCON channel link service.

1. Open Microsoft SNA Server Manager.

2. Open the Servers folder in the left column of the screen.

3. Select the server to which you want to add the link service.

4. On the menu bar, select Insert | Link Service.

5. Select Barr Systems ESCON Channel Link Service.

6. Name the service.

Next, we must define three connections to each of the three LPARs. Each connection uses the same link service. The parameters vary depending on the type of connection the link service uses. The connection parameters for the channel link service describe the VTAM physical unit definition. A channel link service looks like a local major node to the host. Because each LPAR has its own VTAM definitions, the connection has to identify which subchannel (CUADDR) and image (CUADD) it is attaching on.

To configure the logical units or 3270 devices on the SNA gateway, right-click the connection and insert 3270 devices. There must be a corresponding LU defined in the VTAM definition for each LU that you add to the connection.

The VTAM host programmer creates a corresponding definition for each SNA gateway connection. VTAM provides the link between the mainframe and the physical channel connections defined in IOCP.

The following table describes the correlation between IOCP, VTAM, and the SNA gateway.

Host configuration

The following are sample host definitions.

Sample Host Definitions

IOCP describes the channel and devices on the channel to each partition. It is similar to the SCSI BIOS on a PC. Because the SNA gateway with the Barr channel adapter is going to be a shared resource on the mainframe, it is defined in the partition that controls the hardware as a shared resource.

The following are actual host definitions in IOCP and VTAM.

Example

Sample IOCP Definitions

LPARS1, 2, and 3 are defined in IOCP as follows:

Sample VTAM Definitions

The following are sample VTAM definitions. You can create additional LUs as needed.

LPAR1

LPAR2

LPAR3

Summary

The following is a summary of procedures in this topic.

• Define the CHPID that the SNA gateway channel adapter is attached to as a Shared Resource.

• Define the control unit and IODEVICE for each partition.

• Define VTAM nodes in each partition and associate them with the hardware using the CUADDR, which matches the CUNUMBR.

• Define the link service to the SNA gateway.

• Define each connection in SNA Manager, and link it to VTAM using the IOCP definitions, which utilize the subchannel address (E10, E20, E30*) and UNIT ADDRESS.**

*Drop the E since the connection only needs the subchannel number to communicate.

**UNIT ADDRESS is called Control Unit Image on the Connection screen.

References

For more detailed information on the IOCP and HCD definitions, see document number SG24-4037-01 at http://www.s390.ibm.com:80/bookmgr-cgi/bookmgr.cmd/BOOKS/EZ322600/CCONTENTS.